Recordings: Richard Stolzman, clarinet and Richard Goode, piano [RCA Victor Gold Seal 60036-2-RG]; Pinchas Zuckerman, viola and Daniel Barenboim, piano [DG 437 248-2]
Published 1895 (with Op. 120, No. 2).

The clarinet was the inspiration for the last four chamber works composed in the 1890s, and the two sonatas of Op. 120 complete this group.  They are the last pieces of chamber music and the last multi-movement instrumental works composed by Brahms.  Like the Quintet and the Trio, they were written for Richard Mühlfeld, the Meiningen clarinettist whose beautiful playing inspired Brahms to come out of retirement.  Having tried combining the clarinet with both a piano and a mediating string instrument in the Trio and with strings alone in the Quintet, the natural consequence was to combine it with piano alone.  In so doing, he created the earliest clarinet sonatas of any real significance, standards for the instrument to this day.  At the time of their publication, they were also specified for the viola, and they have always been mainstays of that instrument’s sparse repertoire.  The viola can reach a step lower than the clarinet, and many of the changes between the clarinet and viola parts are to exploit the string instrument’s lowest notes or to avoid its rather strained high register.  Some of the changes result in problems with voice leading and balance, however, and Brahms’s role in the preparation of the viola part has been called into question, since most of the part is in a copyist’s hand with Brahms’s corrections.  Nonetheless, the sonatas do work well with the instrument’s rich tone, although they are really heard to their best advantage with the clarinet.  Brahms also produced arrangements for violin which involved even more rewriting, including the piano part.  The violin versions are almost never played.  The piano parts of both sonatas are active, full, and rewarding, with writing similar to that found in the late piano pieces published right before them.

The first sonata in F minor is a carefully planned four-movement structure.  A dark and atmospheric first movement is balanced by an exuberant and extroverted major-key finale.  The first movement is a concise, but thematically rich sonata form, with no less than four distinct ideas in the exposition and an intense, dramatic development section.  The “sostenuto” coda is a glorious inspiration.  The song-like slow movement and the rustic Austrian Ländler that serves as an intermezzo (it is not really a scherzo) are both in the “relative” major key of A-flat, which has the same key signature as F minor.  Having used the four-flat signature for these three movements, Brahms feels freed to turn to the home major key for his rondo finale, something he had never done in a minor-key chamber work.

In the guide, the clarinet version is used for the full analysis.  An abbreviated, more rudimentary guide is provided for a recording with viola, with detailed descriptions of the viola part’s deviations from the clarinet.  The overwhelming majority of these are in the first movement.

ONLINE SCORE FROM IMSLP (First Edition from Brahms-Institut Lübeck--includes piano score [with clarinet], clarinet part, and viola part for both Op. 120, No. 1 and Op. 120, No. 2)
ONLINE SCORE FROM IMSLP (from Breitkopf & Härtel Sämtliche Werke--piano score with clarinet--Op. 120, No. 1 only)
ONLINE SCORE FROM IMSLP (Piano score [with clarinet] and viola part, from a Russian edition, for both Op. 120, No. 1 and Op. 120, No. 2)
ONLINE SCORE FROM IMSLP (First edition from Sibley Music Library--violin arrangement of both Op. 120, No. 1 and Op. 120, No. 2--piano score with violin.  NOTE: The violin version is not considered in this guide.)

Clarinet Version
1st Movement: Allegro appassionato (Sonata-Allegro form). F MINOR, 3/4 time.
0:00 [m. 1]--The piano, in bare triple octaves, presents a four-bar introduction that will play a prominent role later in the movement.  Its shape consists of a series of upward arching figures, a jump up a fourth or third and then a stepwise descent.  The first four longer notes follow this pattern (and establish the key), as do the first two three-note groups in a faster rhythm.  The last three-note group reverses the pattern, stepping up and jumping down.  The last bar is a downward whole step that already introduces a chromatic note, G-flat.
0:08 [m. 5]--Theme 1.  The clarinet sings the wide-ranging, broadly arching theme, which almost has the character of a melancholy waltz.  A short three-note figure in the third measure of the tune recalls the shape of the introduction figures.  The piano plays bass arpeggios, which rest on the third beat of each measure, and a right-hand chord on the second beat of each measure.  Some mild chromatic harmony (such as the note G-flat again) is introduced.  The melody reaches a strong half-close with a descending triplet.
0:20 [m. 12]--The piano introduces sharp, detached dotted (long-short) rhythms.  These leap up and down octaves, including harmonies, while the clarinet continues to spin out its melody.  Another half close leads to a repetition of the initial dotted leaping gesture in the piano, but that instrument settles down into long chords.  The clarinet reaches far lower than it has before in a smooth arching line before returning to its previous figures.  The piano bass then takes up the smooth arching line.  Both instruments taper off in a syncopated line, hesitantly hinting at the “subdominant” key of B-flat minor.
0:42 [m. 25]--Transition, part 1.  The piano strongly asserts F minor again as it now presents a more aggressive version of Theme 1 over a bass in triplet arpeggios.  The clarinet trails the piano.  After the first two bars, the theme itself dissolves into the triplet rhythm.  The clarinet also moves to decorative triplets, including ascending arpeggios, as the piano continues the theme.  At the point where the initial statement had moved to a half-close, the piano introduces strong chords that emphasize the “dominant” C harmony.
0:53 [m. 33]--With another triplet figure in octaves, the piano immediately shifts up a half-step to D-flat.  It returns to the last four bars of the theme, decorated by clarinet triplets and arpeggios as before, but now more forcefully asserting the key of D-flat (which was hinted in the previous passage).  A cadence figure with a descending bass arpeggio in the left hand strongly confirms the key.
1:03 [m. 38]--Transition, part 2.  In rich syncopated chords, the piano presents a new and lyrical idea in the new key (D-flat major).  The clarinet takes over the main rising gestures of the melody.  The tune is short-lived, however.  In its second phrase, the clarinet takes over the melody entirely while the piano, still in its full, syncopated chords, becomes quieter.  Then both instruments seem to become lost and trail off.  This entire passage is often labeled as “Theme 2,” but both it and its key are really too brief to fill that role.
1:31 [m. 53]--Theme 2.  The last bars of the D-flat tune have veered toward the minor.  The last key area of the exposition has been reached (C minor).  The quiet, but agitated theme is built on four short scale figures in a low register, with a distinctive, halting dotted rhythm at the end of these figures.  The piano, with an equally agitated accompaniment, carries the theme, although the clarinet doubles the melody on the first and third figures, the first in its lowest register.  The whole four-bar sequence is then repeated an octave higher with the clarinet taking the melody and the piano moving to breathless arpeggios with the hands in contrary motion.  The piano returns to its original pitch level for the last figure, a descending line.
1:45 [m. 61]--At the end of the last gesture on the second statement of the theme, the clarinet enters with a shrill descending imitation of the figure.  The piano moves to large chords while the clarinet circles down and back up in swirling arpeggios after holding longer, full-measure notes.  The piano chords expand the figures of the theme, retaining the halting dotted rhythm at its original speed.  The first three figures are given with the sweeping clarinet arpeggios, then the last descending piano line is also expanded by one note.  This expanded, seven-bar variation of the theme is closed by a sharp half-cadence in full piano chords on the dotted rhythm.
1:58 [m. 68]--The piano begins a powerful pattern of arpeggios in contrary motion with the right hand moving in and out and the left hand, spaced widely below, going the opposite direction.  The pattern begins on the second beat, with a group on each beat.  The first right-hand note of each group forms a stepwise descending line, which is imitated (in canon) two beats later by the clarinet, so the clarinet begins its line on the downbeat.  There are two descents of five notes, each beginning a step lower.  The piano begins its second descent on a downbeat.  As the clarinet completes its imitation of the second descent, the piano plays two sharp chords that suddenly avert a full cadence in C minor.
2:05 [m. 72]--The volume suddenly becomes softer.  It is now the clarinet’s turn to lead an imitation in canon.  It plays a series of “sighing” broken thirds, moving steadily downward by step, beginning on the second beat.  There are two five-step descents, the second one beginning after a downward leap of a fifth.  The piano left hand plays rapid upward arpeggios against these.  Its right hand imitates the broken thirds two beats later, beginning on the downbeat.  After the clarinet completes its second pattern, the left hand pauses its arpeggios.  The right hand and the clarinet then also pause for a beat, during which the left hand plays an arpeggio.  This alternation continues twice more as the volume further diminishes.  The piano right hand completes its imitation while the clarinet leaps down for two more thirds that are not imitated, as if beginning another descent, reaching to its lowest notes.  The last figure from the right hand and the clarinet is not followed by a left hand arpeggio, and there is a complete pause on the last upbeat.
2:14 [m. 77]--Closing section.  After the pause, the piano plays a forcefully surging upward line in full harmonies, with its left hand leaping down to very low octaves.  This is followed by a rapid descending arpeggio from the clarinet, beginning very high and pausing on the second beat.  This pause is supported by cross-rhythm chords in the piano right hand and rolled chords in the left.  A cadence gesture is followed by another upward piano surge, but this time it reaches further with intensified harmonies.  After three quick descending clarinet figures, the piano right hand repeats the original clarinet descent, now from an even higher level (up a fourth), with a treacherous leap, accompanied by thick rolled chords in the left hand.
2:30 [m. 86]--The clarinet immediately follows the piano with the descent from the heights while the piano continues to play thick chords.  Then both instruments finally settle down to a full cadence in C minor, which is reiterated with the piano bass on the downbeat and the right hand, with clarinet, on the second beat.  The volume rapidly diminishes over this cadence, and the exposition comes to a full close, piano, complete with a soft double bar line.
2:40 [m. 90]--The bass C in the piano is used to pivot to A-flat major (related major key to the home key of F minor).  There, the lyrical idea originally presented in D-flat (indicated as Transition Part 2) is given at a lower pitch and provided with dreamy extensions.  Both the clarinet responses and the piano bass are decorated with three-note turn figures derived from the opening piano introduction.  It becomes increasingly warm and expressive, with low, silky clarinet tones and the piano returning to the opening gesture of the introduction, before being abruptly diverted.
3:00 [m. 100]--An A-flat that would have served as a cadence note is re-spelled as G-sharp and used to divert the cadence to the unexpected key of E major.  There, the dreamy mood of the lyrical theme, combined with the figures from the piano introduction, continues.  These three-note figures are passed from the clarinet to the piano left hand, which climbs up into the tenor register.  Two similar figures with large leaps downward in the left hand suddenly divert the music yet again, now from E to its related minor key of C-sharp.  These are each followed by two beats of expectant, ominous silence.
3:31 [m. 116]--In a sudden outburst in C-sharp minor, the lyrical theme is transformed into a passionate cry.  The clarinet practically wails the first syncopated notes while the piano, breaking into triplets, plays the characteristic rising gestures.  The piano texture is thick, with thunderous octaves in the left hand.
3:39 [m. 120]--Theme 2 returns, also in C-sharp minor, retaining the passionate mood that has just been established, and played in full harmony.  The gestures of the theme are recognizable, but they now spread across a wider range.  The piano expands the closing dotted rhythms with rapid descending figures harmonized in thirds while the clarinet punctuates them.  On the last descending gesture of the theme, the clarinet enters in imitation, as it had done at 1:45 [m. 61].  This time, the initial imitation is not in the high, shrill register.  There is now a second imitation with both instruments jumping to the high level.  The clarinet then drops out and the piano continues, overlapping the last clarinet figure, repeating its descending line, and moving steadily downward.  The left hand plays marching low bass octaves.  They key moves to F-sharp minor, and the clarinet enters again as a cadence in that key is approached.
3:57 [m. 130]--At the climax, the piano introduction returns in F-sharp minor, a half-step higher than the home key.  It is passionate and intense, with harmonies added to it that create a strong sense of syncopation.    The clarinet plays two descending, syncopated octaves at the moment of return, then the piano is left alone to complete the statement.  After the four bars of the introduction, four more are added as a transition to the reprise and a relaxation of the passionate climax.  The first two simply repeat the last chords an octave lower and with added clarinet, but the last two artfully and quietly shift to the home key of F minor.  They have very low triplet arpeggios in the bass, descending arpeggios in the right hand, and long clarinet notes.
4:15 [m. 138]--Theme 1.  Both the clarinet and the piano parts decorate the melody with triplet arpeggios derived from the repetition at 0:42 [m. 25].  The triplets in both hands of the piano are far more dynamic than the previous straight arpeggios in the bass.  The clarinet starts an octave lower than it did in the exposition, but quickly uses a rapid ascending arpeggio in triplets to reach the higher octave.  The half-close arrives as expected.
4:28 [m. 145]--The continuation of the theme from 0:20 [m. 12] and the first part of the transition that began with the repetition of the theme at 0:42 [m. 25] are conflated into a much shorter transition passage.  It begins with the sharp, detached leaps in a dotted rhythm, as expected, but the harmony breaks into dissonant “diminished seventh” chords.  The piano plays chords in the rhythm of the theme, with the left hand continuing the octave leaps in the dotted rhythm.  The clarinet, meanwhile, breaks into a series of dynamic descending two-note figures.  These diminish in volume and suddenly lead with quiet piano chords into the lyrical melody, which arrives much earlier than expected.  The passage ends where it began, on the expectant “dominant” chord in F.
4:44 [m. 153]--Transition theme (Transition part 2).  The lyrical melody is presented without change from its presentation at 1:03 [m. 38] except that it is now a third higher, in the home major key (F major).  The only change from the otherwise analogous presentation is in the very last chord, whose direction in the piano is altered to allow the music to remain in F (but moving back to minor) instead of shifting down a half-step for Theme 2, as it had done in the exposition.
5:13 [m. 168]--Theme 2.  It is now played in the home key of F minor, with little alteration except for the absence of the clarinet in the first four bars.  The clarinet enters with the repetition of the theme against the breathless piano arpeggios in contrary motion.
5:27 [m. 176]--As at 1:45 [m. 61], the clarinet imitates the descending figure, but because of the transposition of the music up from the exposition, it is brought down to the lower octave (due to the clarinet’s range), and it is not as shrill.  The piano still plays the large chords that expand the theme’s rhythm.  As the clarinet breaks into the swirling arpeggios, artful manipulation of them (jumping up instead of down at strategic points before a fast group of notes--and vice versa) allows the player to move to the higher octave, then back to the lower one.  As before, the sharp half-cadence follows the last piano descent.
5:40 [m. 183]--The powerful arpeggios in contrary motion, with the clarinet entering in canon, follow as before at 1:58 [m. 68], but Brahms intensifies the rhythm of the piano part.  After the first two arpeggios, which begin as expected, the clarinet enters in canon with the top notes, also as expected.  But at that point, Brahms changes the piano arpeggios from four notes to three, creating a hemiola (cross-rhythm).  With four arpeggios in the measure, the last top note is simply repeated to preserve the canon.  The piano bass, which previously moved steadily up through both descents, leaps back down for the second one.  The same pattern is used for the second piano descent, but on the first two arpeggios, the low bass line of the left hand keeps up the rhythmic intensity by adding a chromatic ascent in a dotted rhythm.  Because the three-note arpeggios now start on the upbeat, the second of these creates a very strong syncopation across the bar line.  The clarinet “ignores” these rhythmic games in the piano.  The closing chords restore order.
5:48 [m. 187]--Here, the pattern of imitation between the “sighing” broken thirds of the clarinet and the piano right hand, with bass arpeggios, is largely retained from 2:05 [m. 72].  The pauses and diminishing volume, in anticipation of the closing section, follow as before.  Because of the higher key, the clarinet does not reach down to its very lowest notes as it had before.
5:56 [m. 192]--Closing section.  It begins as at 2:14 [m. 77] with the piano surge, but again, the higher key requires the following clarinet descent to be in the lower octave.  After the second piano surge and intensification, the descending arpeggios are redistributed.  The piano right hand takes the last of the three quick clarinet descents, and then the clarinet spares the piano its treacherous leap by taking the original descent (again a fourth higher) with the pause on the second beat.  The left hand retains its thick rolled chords.  The clarinet leaps to a higher register for the following cadence gesture.
6:12 [m. 201]--In another reversal, the piano begins the last descent from the heights, but the clarinet quickly takes over on the second beat, replacing the expected pause and syncopation with a continuation of the descending line.  Instead of diminishing and settling to a cadence, as happened at the end of the exposition after 2:30 [m. 86], the piano follows the clarinet descent with a stark transformation of the first notes from the main theme.  Over four bars, low octaves on the first beat are followed by full chords on the second.  The top notes of these chords outline the first three notes of the theme, shifting down an octave for the third of these, which is preceded by a single low F instead of an octave and harmonized by a bare open fifth.  The volume rapidly diminishes.  The fourth bar is a repetition of the third, replacing the hollow fifth with the full F-minor chord.  An inner voice in these last two bars repeats the first two notes of the theme.
6:22 [m. 206]--The clarinet mournfully sings out the main theme, an octave lower than its first appearance.  Unexpectedly, it is altered to make a hopeful shift to major.  The piano maintains the pattern of the previous bars, with the throbbing low F on the first beat of each bar followed by an octave or chord on the second beat.  After the fourth bar of the theme, the clarinet soars upward in a triplet arpeggio.  This leads to an elaboration in B-flat minor of the triplet figures from the repeated appearances of the theme.  These are passed between the piano and clarinet in an improvisatory manner.
6:40 [m. 214]--As the triplets shift back to F minor, Brahms marks the remainder of the movement “Sostenuto ed espressivo.”  The triplets are now spun into a melancholy reverie with evocative, strumming rolled chords in the piano.  As the phrase reaches a cadence, straight rhythms are introduced, with the instruments alternating and playing straight duple rhythms against the triplets (two against three).
6:57 [m. 219]--The first “sostenuto” phrase elides into a varied repetition at the cadence.  The clarinet first delays its figures, then expands and intensifies them, building to the last climax of the movement, where the duple patterns, also delayed and without as much two-against-three playing, return.  The clarinet breaks off on a descending line, which the piano haltingly continues, avoiding a cadence and re-introducing the triplets in the bass while settling back down.  It is similar to the end of Theme 2.  The phrase, now a full eight bars, ends on a highly expectant “dominant” harmony and a tolling low C in the piano bass.
7:25 [m. 227]--A version of the four-bar introduction provides the material for the closing bars.  The piano states it first in low octaves punctuated by a higher tolling C.  It is recast so that it begins on F and the opening leap is a fifth, pulling down toward the home keynote.  After two bars, marked sotto voce, the piano plays two low, reinforced open fifths, F--C.
7:38 [m. 231]--Now the clarinet plays the first two bars of the introduction on their original pitches, ending with long reiterations of the note C.  Under this, the piano chords make a definitive shift from F minor to F major, which is outlined in a long arpeggio moving from the low bass up to the final chord.  This widely spaced F-major chord is closed by a leap down to a final low F in the left hand.
8:06--END OF MOVEMENT [236 mm.]

2nd Movement: Andante un poco Adagio (Ternary form with varied return).  A-FLAT MAJOR, 2/4 time.
A Section
0:00 [m. 1]--The clarinet presents the highly lyrical, but somewhat forceful theme while the piano accompanies with slow descending patterns that make wide leaps down from the tenor register to low bass notes.  Brahms directs that the notes of these descents are to be sustained through the bar.  The clarinet theme itself is characterized by gentle turning figures.  Chromatic notes are quickly introduced.
0:16 [m. 5]--The clarinet introduces wide leaps while the piano moves away from the slow descents.  The piano becomes gradually more active, with bass notes off the beat.  The clarinet, in an expressive line, veers toward a cadence in the “dominant” key of E-flat, which is delayed by the piano with a “deceptive” cadence that imitates the clarinet figure.  The clarinet then completes the E-flat cadence, but an ascending arpeggio moves directly back home to A-flat and the opening melody.
0:47 [m. 13]--The opening melody returns, but it is now marked dolce as opposed to the stronger first presentation.  The first three bars are as in the first statement, but the fourth bar reaches higher in the clarinet, avoiding a motion away from the home key.  The piano harmony is also changed in that bar.
1:03 [m. 17]--Instead of the wide leaps heard at 0:16 [m. 5], the clarinet steadily works upward, but in a similar rhythm.  The piano line is more urgent, introducing an active inner voice.  The expressive line is abbreviated, and the clarinet moves directly to the cadence figure, which is now forceful, excited, and in the home key.  The piano diverts it with the “deceptive” imitation, as before, but the clarinet restores order and reaches a lower, full cadence as the music rapidly settles down.  A reiteration of the clarinet’s last note is supported by a new chord in the piano, the “dominant” of D-flat, the key in which the B section will begin.
B Section--D-flat major
1:28 [m. 23]--The piano begins a gentle, lilting pattern of arpeggios whose leaps up on the fourth notes of four-note groups suggest a dotted rhythm.  This is confirmed by the rhythm in the left hand.  In the second bar of this first pattern in D-flat, the clarinet adds a descending figure, also in a dotted rhythm.  The entire two-bar sequence is then shifted down a whole step, to C-flat major, and played at an even quieter level.
1:44 [m. 27]--Under a sustained D-flat in the clarinet, the piano plays chromatic arpeggios with a slowly moving bass.  These, and the following clarinet line, build slightly and lead back to D-flat, initially in its minor version (notated as C-sharp minor in the piano).  The passage is extremely colorful and evocative.  A cadence in C-sharp (D-flat) minor is averted by a resumption of the initial lilting arpeggios in major.
1:58 [m. 31]--The lilting arpeggios are now transferred to the clarinet.  The direction is changed on the first beat, and it begins with a rest, but the pattern is still recognizable.  The piano adds a series of descents between two-note harmonies.  These descents in the right hand dovetail with isolated downward leaps in the left hand.  As before, the whole pattern is repeated in C-flat, but both instruments also leap down an octave, adding to the evocative sense of mystery.
2:12 [m. 35]--A pattern similar to that at 1:44 [m.27] begins.  The piano arpeggios with the slow-moving bass are very similar, as is the sustained clarinet D-flat (beginning a beat later) and the patterns that follow.  Instead of moving to D-flat/C-sharp minor, however, the music almost immediately shifts to that key’s “relative” major, E major (Brahms even changes the key signature in the piano for the first time in the movement).  The patterns in both instruments are extended another two bars to confirm the arrival of this unexpected key.
2:32 [m. 41]--A cadence in E major is interrupted by the unexpected appearance of the main theme from the A section in that key.  It is played by the piano for the first time, in a high register, with the clarinet taking over the wide descents initially heard against the theme.  After the first two bars, the theme is dramatically diverted in direction and harmony.  Triplet (sextuplet) rhythms are introduced, as are “diminished” harmonies.  The winding triplets in the piano become move and more nebulous.
2:48 [m. 45]--The nebulous harmonies emerge into another statement of the main theme of the A section in the piano, this time a major third lower, in C major.  The piano shifts down an additional octave, lower than the initial presentation of the theme in A-flat in the A section.  The clarinet is completely absent this time, the wide descents being simplified and moved entirely to the left hand.  In the third bar, a similar diversion with triplet rhythms and diminished harmonies occurs, leading to a similar abrupt shift down a major third.
A’ Section
3:04 [m. 49]--The shift down a major third from C major means that the music has artfully arrived back at the home key of A-flat major.  The clarinet is transposed down an octave for the entire first statement of the main theme.  The first four bars are expressive and quiet, as at 0:47 [m. 13] rather than the opening.  The melody and harmony, however, match the opening except for the lower octave.  The piano, instead of the long, slow descents, is given more decorative descending arpeggios in triplet rhythm, omitting the first note of the first beat of the bar, and punctuated on the second beat by the same low notes.
3:20 [m. 53]--The continuation of the clarinet line is as at 0:16 [m. 5], with the motion toward E-flat, but still an octave lower.  The piano continues to move in triplet arpeggios against the familiar bass, but these introduce more syncopation.  At the “deceptive” cadence, the right hand moves away from the arpeggios to imitate the clarinet line, which has now moved to the instrument’s lowest notes.  The left hand still plays two triplet arpeggios against this.  At the two bars with the cadence and the rapid motion back to A-flat, the clarinet moves back to the original higher octave and the piano plays its original notes.
3:52 [m. 61]--For the second statement, the clarinet remains in the original higher octave and matches the statement at 0:47 [m. 13].  The piano arpeggios, still in triplets beginning off the beat, are now played by both hands in contrary motion rather than in single descents split between the hands as at 3:04 [m. 49].
4:07 [m. 65]--The clarinet line matches that at 1:03 [m. 17], still becoming excited and reaching a climax before the “deceptive” cadence.  The triplet arpeggios in contrary motion continue in the piano until the climax, where the right hand continues to play the triplets while the left moves to solid bass notes.  The right hand again takes up the imitation at the “deceptive” cadence, playing it against a couple more triplet arpeggios in the left hand.  In the last two bars, the piano moves back to “straight” rhythms.  At the final cadence, the clarinet line introduces syncopation and a dotted rhythm, continuing to move down beyond the cadence note to a low E-flat, introducing the coda.
4:32 [m. 71]--The coda uses the lilting arpeggios characteristic of the B section, complete with the clarinet response in dotted rhythm.  It begins in A-flat, but the chromatic note G-flat is prominently introduced.  This suggests both E-flat minor and D-flat major, but the music does not move to either key.  Instead, the arpeggios build to a forceful climax over two bars, culminating in a high G-flat and a dissonant descent with “diminished” harmonies.  The clarinet is absent for this climax and descent.
4:48 [m. 75]--After the piano descent, the clarinet enters with one last statement of the main theme’s opening in A-flat.  It is played in the original high octave.  At the fourth bar, the melodic line “stalls” on the note C, sustaining it in three syncopated notes, each a half-beat longer than the last, until finally moving to A-flat in the last bar.  The piano line here resembles the slow descents of the opening, but a high octave is placed between a chord on the first beat and the expected low note (now a pedal-point A-flat) on the second.  These mildly syncopated high octaves form a four-note chromatic descent before leaping down an octave against the syncopated C’s.  These C’s in the clarinet stretch this last phrase to an irregular seven bars.  Before this, the entire movement is built on regular phrases of two, four, or six bars.  In the last two bars, the piano abandons its pattern, closing with two chords under the final clarinet motion to A-flat.
5:30--END OF MOVEMENT [81 mm.]

3rd Movement: Allegretto grazioso  (Ternary form resembling a scherzo and trio).  A-FLAT MAJOR, 3/4 time.
A Section (“Scherzo”)
0:00 [m. 1]--Part 1.  The melody and its accompaniment begin on an upbeat.  Although gentle, the rhythm, with long notes on the downbeats followed by three-note upbeats, suggests the Austrian “Ländler,” a waltz-like peasant dance.  In the third and fourth bars, the piano right hand subtly imitates the rhythm of the clarinet.  The first phrase is not in A-flat, but is set rather emphatically in the “dominant” key of E-flat.  The shift to A-flat begins in the second bar of the second phrase, which closes with a “plagal” cadence.
0:12 [m. 9]--Part 1, varied repeat.  The melody is transferred to the piano right hand, leaving the clarinet to decorate it with three-note groups and other figures both on and off the downbeats.  The harmony, moving from E-flat to A-flat, is as in the first statement.
0:23 [m. 17]--Part 2.  The mood suddenly becomes more boisterous.  The Ländler rhythm continues.  In the first phrase, the clarinet blasts it out in its lowest register, with full and rich piano accompaniment.  A second phrase begins as if moving the first one up an octave, but the clarinet figures diverge in the third measure, stalling on an upward moving line.  Meanwhile, the piano shifts the harmony to D-flat.
0:34 [m. 25]--The piano takes over the clarinet figures in four transitional bars.  The clarinet plays a two-note descent for the first two, then the piano also takes that over alone in the last two, with syncopation in the left hand.  These last piano chords shift from D-flat to E-flat for the resumption of the main melody.
0:40 [m. 29]--The melody from Part 1 returns, along with its gentle mood.  For the first phrase in E-flat, the piano plays the melody.  The clarinet accompanies with more elaborate figures than it had at 0:12 [m. 9].  The second phrase, which still makes the familiar shift to A-flat, is completely transformed.  The clarinet spins its first two measures out into full six-note groups, and the piano follows suit in the accompaniment.  The last two measures still contain the “plagal” cadence, but the clarinet changes the direction of its lines to make them more questioning.  These last two bars are repeated with the clarinet an octave lower and the piano right hand an octave higher.
0:54 [m. 39]--A small “codetta” is added.  The clarinet begins by spinning its last figures upward for two bars without the piano.  The piano then enters with soothing chordal descents as the clarinet continues to work upward.  The clarinet finally reaches a resting point on a high A-flat.  It then jumps down to the lower octave for the final cadence, which is warmly concluded by a descent in the piano.  The last bar (m. 46a) serves as a “first ending,” with its upbeat beginning the repeat of Part 2 and suddenly returning to its boisterous mood.
1:05 [m. 17]--Part 2 repeated.  Boisterous variation of the melody, as at 0:23.
1:16 [m. 25]--Transitional passage, as at 0:34.
1:21 [m. 29]--Return and variation of main Part 1 melody, as at 0:40.
1:36 [m. 39]--“Codetta,” as at 0:54.  The second ending (m. 46b) is conclusive.
B section (“Trio”)--F minor
1:49 [m. 47]--Part 1.  The piano, marked “molto dolce,” begins a long descent of two octaves in its left hand, interrupted by occasional leaps down and back up.  The right hand also descends, but it begins a third higher, doubled an octave above for a very high sound, and a half-beat later, creating syncopation across the bar.  The directional imitation is not exact, and the right hand typically leaps up after the left leaps down.  The clarinet, meanwhile, plays sustained notes with very little activity in its lowest register.  In the last bar, the piano left hand leaps down, and a full F-minor cadence is averted.  The phrase ends on the “dominant.”
2:01 [m. 55]--Part 1, varied repeat.  In the first four bars, the clarinet drops out.  The piano left hand adds a lower voice that approximates the clarinet notes.  This supersedes some of its downward leaps.  The right hand is unchanged.  These bars are marked pianissimo, quieter than the first statement.  The clarinet enters for the last four bars, and the piano returns to its original pattern.  The last bar is altered in both instruments to suggest a motion to E-flat major rather than the “dominant” of F minor.
2:13 [m. 63]--Part 2.  The piano continues its quasi-imitation between the hands, usually a third apart, but now closer to the middle of the keyboard and with an added bass voice.  The clarinet now moves into its stronger middle register and a more soaring line.  Part 2 begins with a shift to A-flat major with many chromatic notes.  It then appears to move back to E-flat with a distinctive, emphatic four-note gesture in the clarinet which is then more quietly inverted.  The gesture and its inversion are repeated with altered harmony, and the key moves back to the home key of the “trio,” F minor.  The key is confirmed in four more forceful bars based on the previous clarinet gestures, with full chords in the piano.
2:36 [m. 79]--The expressive last phrase is very similar to Part 1, but with many role reversals and other changes.  The left hand still leads, but now the clarinet plays along with it.  The left hand has a descending line harmonized in thirds with many notes doubling the clarinet line.  The clarinet plays the line originally played by the right hand, but on the beat.  The right hand, playing after the beats as before, now plays a line more closely resembling the original left hand descent, but its leaps typically follow the direction of the clarinet.  The first six bars follow Part 1 relatively closely, then two extra bars are inserted before the last two reach a full F-minor cadence, the clarinet again descending to the low register and fading away.
2:51 [m. 63]--Part 2 repeated.  Soaring phrase in A-flat and E-flat with motion to F minor, as at 2:13.
3:14 [m. 79]--Closing phrase similar to Part 1, as at 2:36.
3:28 [m. 89]--Two repeated F’s, spaced two octaves apart in the tenor and low bass registers, are played in the piano to more fully close the “trio” section.  The first of these is on the second beat of the bar, creating rhythmic uncertainty.  The second is marked with a fermata, allowing breathing space before the return of the main Ländler (A section).
A’ Section (“Scherzo”)
3:34 [m. 91]--Part 1.  The repeat of the Scherzo/Ländler is written out, although the only difference is a further “variation” on the varied repetition of Part 1 and the absence of a Part 2 repeat.  This first statement of Part 1 is not changed from the beginning other than a new marking of “teneramente.”
3:46 [m. 99]--Part 1, varied repeat.  As at 0:12 [m. 9], the piano right hand takes the melody.  But now the clarinet is removed from the phrase and the left hand is much more active, with widely spaced arpeggios.
3:57 [m. 107]--Part 2.  All of Part 2 is essentially the same as its first two statements.  Boisterous variation of the melody, as at 0:23 and 1:05 [m. 17].
4:08 [m. 115]--Transitional passage, as at 0:34 and 1:16 [m. 25].
4:14 [m. 119]--Return and variation of main Part 1 melody, as at 0:40 and 1:21 [m. 29].  Brahms adds “più dolce sempre” to the last four bars (the closing bars and their repetition with octave shifts), indicating that he wishes a greater sense of closure at the end of the movement than before the “trio” section.
4:28 [m. 129]--Final “codetta,” as at 0:54 and 1:36 [m. 39].  Brahms adds the marking “calando” at the piano entry.
4:48--END OF MOVEMENT [136 mm.]

4th Movement: Vivace (Rondo form).  F MAJOR, Cut time (2/2).
0:00 [m. 1]--Introduction.  The piano begins with three tolling repeated F’s that will serve as a unifying device for the movement.  Under this fanfare-like gesture, a vigorous accompaniment begins with treacherous broken octaves in the left hand.  The fanfare spins out into a melody that serves as a call to action.  The clarinet enters with an upbeat flourish as the piano plays its final chords.  This is immediately repeated an octave lower and at a suddenly quieter level in preparation for the actual rondo theme.
0:11 [m. 9]--Part 1 (a).  The clarinet presents the grazioso rondo theme, which is characterized by a cheerful buoyancy and a light touch, especially in a series of staccato two-note repetitions.  The accompaniment is also smooth, then light, gliding up the keyboard, then bouncing with the staccato notes.  In the low bass, however, the three repeated F’s ring out twice as a foundation.  The last two bars make a seamless turn from F major to A minor.
0:21 [m. 17]--Part 2 (b).  The piano plays a downward arching arpeggio in octaves, which emerges into chords moving from A minor to A major.  The clarinet then takes the same arpeggio a fourth lower, on the “dominant” of A, doubled an octave lower by the piano left hand.  The clarinet notes played against the following chords artfully slide back to the rondo theme in F major.  They are in fact a huge expansion of the theme’s opening upbeat over two measures.
0:32 [m. 25]--Part 3 (a’).  The first four measures of the theme are played as before, with the tolling low F’s.  The second phrase diverges, expanding in scope and in volume.  The opening upbeat becomes prominent, and the last bar of the phrase merges with a return of the tolling three F’s, now in the clarinet over pure F-major harmony.  The following three-note descent comes directly from the introduction.  The F’s and the descent are repeated again, with the piano right hand chords shifted down a third.
0:46 [m. 36]--Transition.  Most of it is played by the piano alone, building off the gestures from the introduction and moving to C major.  The last descending arpeggio is imitated a fourth lower by the clarinet, which enters at the last minute, quieting things in preparation for the first contrasting theme (B).
0:54 [m. 42]--The theme is based on triplet motion.  Nonetheless, a link to the rondo theme remains, as the three tolling repeated notes again establish themselves in the bass, now transposed from F to C.  The right hand of the piano, in the tenor register above the tolling C’s, presents the theme, which is in broad triplet rhythm and consistently harmonized in warm, rich sixths.  The clarinet adds leaps up two octaves, also in triplet rhythm. 
1:00 [m. 46]--The second phrase shifts the first up an octave, and the clarinet adds a harmony a third above it, an octave above its lower sixths.  The two octave leaps move to the piano bass.  The last bar of the phrase is altered.  The sixths contract to thirds and slide down chromatically.  The clarinet then takes over the melody, repeating the top piano notes of the previous bar, a repetition not present in the first phrase.
1:06 [m. 50]--The altered ending of the previous phrase leads to a new, soaring line in the clarinet, still in the broad triplet rhythm.  A two-bar unit is repeated a step higher.  The piano takes on a rocking motion, also still in triplets.
1:12 [m. 54]--The triplet rhythm is suddenly broken by a light variation of the previous soaring phrase, the clarinet directly imitating the piano right hand in straight eighth notes, but with the opposite octave shifts, the clarinet shifting down after the piano shifts up and vice versa.  The left hand plays isolated rolled chords.  After this variation, strong chords in the piano, their top line imitated a bar later by the clarinet, lead into the re-transition, pausing with a sustained chord on the “dominant” of C major.
1:23 [m. 62]--Re-transition.  The clarinet plays the opening repeated-note gesture of the introduction, but on C instead of F.  The piano responds with its own figures from the accompaniment to the introductory fanfare.  The clarinet then joins these in harmony.
1: 28 [m. 66]--The clarinet plays the three repeated C’s an octave lower.  The piano left hand joins it, but with a clashing harmony a step lower, on B-flat.  This B-flat announces the move back to F major.  The right hand of the piano begins an excited passage derived from both the rondo theme and the triplet theme.  Two-note harmonies alternate with higher single notes.  These harmonies begin with sixths, but then include fourths, fifths, and thirds.  The right hand bounces around the keyboard with this pattern, the left hand adding strong punctuating chords.  After dropping out for five bars, the clarinet artfully enters with its two upbeat flourishes from the introduction, the second still quieter and an octave lower, as the piano settles into the last chords of that introduction, announcing the return of the rondo theme.
1:42 [m. 77]--Part 1 (a).  As at 0:11 [m. 9].
1:53 [m. 85]--Part 2 (b).  As at 0:21 [m. 17], but the clarinet is dropped from the second phrase, and its top line is taken by the piano right hand, including the slide back into the main rondo melody.  Thus, Part 2 is now a solo passage for the piano.
2:04 [m. 93]--Part 3 (a’).  The first phrase is subtly varied from 0:32 [m. 25].  In the first two bars, the parts are reversed so that the piano right hand, rather than the clarinet, takes the melody.  The clarinet plays the arpeggios previously heard in the piano.  The three low F’s are still there.  After these two bars, the clarinet drops out, and the piano alone plays a variation, with broken octaves, of the light staccato passage.  The second phrase is as it was before, with the expansion and intensification, but it comes to a complete close rather than merging into a return of the repeated F’s.
2:13 [m. 101]--Transition/Development.  The clarinet again drops out as the piano plays a very extroverted, fully harmonized variation of the arpeggios from Part 2 of the theme (b).  The left hand now plays in contrary motion, with wide leaps.  The variant is heard in C major, then a third lower on A major.
2:19 [m. 105]--A major leads to D minor, the related minor key to the home key of F major.  There, the clarinet enters with the beginning of the rondo theme in a minor-key transformation.  The three repeated notes, low in the bass, are now on D.  After two bars, the clarinet drops out, and the formerly light, staccato part of the theme is now played in heavy bass octaves with middle-register off-beat chords in the right hand.
2:24 [m. 109]--The theme continues in D minor, harmonized in sixths and thirds with undulations in the clarinet’s lowest register.  After two bars, the theme begins to trail off with a series of descents in doubled thirds and sixths.  Things become more fragmentary until a short-long rhythm is passed between the piano and the clarinet and the volume settles down to a subdued level.  These short-long rhythms anticipate the dotted rhythm of the second contrasting theme (C).
2:38 [m. 119]--The theme is marked semplice, and indeed it is simply structured.  The main argument is a long-short dotted rhythm followed by another longer note on the third beat of the bar.  The shorter note is usually a step higher than the longer ones.  The first four-bar phrase is taken by the piano alone, with left hand chords on the second and fourth beats.  The third and fourth bars have leaps up a fourth and a third in straight rhythm.  This phrase is answered by the clarinet, which begins lower, but expands the dotted rhythm with wider leaps of a fifth, leading to a closing descent.  Under the clarinet, the left hand plays a bass line on the strong beats, with the right hand taking the harmonies on the second and fourth beats.
2:49 [m. 127]--The two phrases are now varied, with their presentations reversed.  The clarinet takes the first phrase, adding flowing decorations to the last two bars.  The piano maintains its pattern from the previous phrase with a bass line on the first and third beats.  Then the second phrase is played by the piano alone, beginning at the same pitch level as the clarinet did when it played it.  The last two bars of this phrase are also decorated with more active notes, and they build in volume.
3:01 [m. 135]--A third sequence appears to begin that is similar to the previous one at 2:49 [m. 127], with the clarinet beginning, but the piano immediately adds loud syncopated chords, and at the third bar, the phrase takes a new turn, the clarinet leaping down an octave and repeating the first gesture there, suddenly back at the initial quiet level.  The line then moves downward and the key shifts back to F major.  The second phrase never appears, the first phrase moving into a transition over seven bars.  The last two bars are a wonderfully extended cadence in F major, with anticipatory pauses after the notes A and G.
3:12 [m. 142]--The presentation of the theme in the home key is analogous to 0:54 [m. 42], but with the parts re-arranged.  The low tolling F’s (rather than C’s) are now in the clarinet.  The two-octave leaps are in the piano right hand, and the triplet melody, still harmonized in sixths, is in the left hand.
3:18 [m. 146]--Analogous to 1:00 [m. 46], with the same arrangement in the piano—harmonized melody in the right hand, two-octave leaps in the low bass.  The clarinet harmonization of the melodic line, however, is not present.  Instead, the clarinet leaps up an octave with the groups of three tolling F’s.  At the end of the phrase, where the clarinet took over the melody before, those notes are added to the chords of the piano right hand.
3:25 [m. 150]--Analogous to 1:06 [m. 50].  The soaring line formerly played by the clarinet is now taken by the piano in octaves.  The right hand follows behind the left, playing off the beats, creating broken octaves and syncopation.  The rocking lines heard before in the piano are transferred to the clarinet, which also plays in broken octaves.  All lines are still in the triplet rhythm.
3:31 [m. 154]--Analogous to 1:12 [m. 54].  The variation in straight eighth notes is essentially unchanged, but the clarinet is absent.  All of the imitations and octave shifts are played by the piano right hand, which must make rapid, treacherous leaps, while maintaining a light touch, to accomplish them.  The left hand still plays rolled chords.  The section that follows is also similar, but the clarinet, entering briefly, leads into the strong piano chords.  The passage is also extended by three bars and intensified, emphasizing syncopated piano chords and ending with a descent of first-inversion chords in the right hand.
3:42 [m. 163]--Re-transition.  Instead of landing on the “dominant” chord as before, the previous passage deceptively moves a half-step higher than expected, to a chord on D-flat.  The clarinet plays the tolling motto of three repeated notes on that pitch, and the piano follows with rising octaves on it, heavily emphasizing and establishing the note while greatly diminishing in volume and intensity.  The piano harmonies then confirm the key, and the clarinet plays the motto notes an octave lower.  D-flat is then re-interpreted as C-sharp and used to pivot to A, where the clarinet again plays the motto notes.  The piano uses that pitch (as the third of F) to move back home to F at a very quiet level.  This brief diversion far afield from the home key serves to set up the last, varied return of the rondo theme.
3:57 [m. 174]--The introductory fanfare suddenly and triumphantly returns, now blasted out by the clarinet, the piano now taking only the busy accompaniment.  Unexpectedly, it is expanded and spun out, doubled in length and culminating in a clarinet arpeggio that seems to divert to C major.  Another two-bar extension, suddenly quieting down, leads back to an arrival on F and at the theme with a descending clarinet arpeggio.
4:10 [m. 184]--Part 1 (a).  The harmony and contour of the theme are still recognizable, but its character is completely changed.  The entire first phrase takes on the character of the light staccato portion, with the grazioso element completely removed.  The right hand imitates the left an octave higher and after the beat.  The clarinet adds punctuating staccato notes in its low register.  The octave imitation breaks after two bars.  The second phrase is suddenly louder and based on syncopated chords, again with the right hand imitating an octave above the left.  The clarinet settles things down with the expected motion to A minor as the staccato figures, now more isolated, return in the piano.
4:19 [m. 192]--Part 2 (b).  Again, the harmony is recognizable, but the arpeggio element is replaced by block harmonies, brief upbeat clarinet figures retaining a bit of the previous character.  It begins forcefully, but quiets down as it becomes more active.  A similar pattern follows with the second phrase.  Half-step descents in the clarinet lead to the same four notes that had expanded the upbeat and slid back into the rondo theme (Part 3) as heard before.  They provide the strongest link back to theme in its original form.
4:30 [m. 200]--Part 3 (a’).  This last section, finally, returns to the familiar version of the theme as heard at 0:32 [m. 25].  The first seven bars are presented as they were there, including the low tolling F’s and the exhilarating expansion.  There is a sense of return, relief, closure, and satisfaction.
4:39 [m. 207]--As in the first statement, the cadence merges into a return of the repeated-note motto in the clarinet, with chords and arpeggios in the piano.  The first two measures follow the expected pattern, but then the motto is shifted up to A and the piano figures become more excited.  The passage expands into a brilliant coda based on the introductory fanfare.  Figures from that introduction are passed between the piano and the clarinet.  A clarinet trill leads to the last flourishes and chords.  The clarinet plays two rising arpeggios in triplet rhythm before the final clinching chords.  These are punctuated by the three repeated F’s, the last leaping down an octave to provide an emphatic close.
5:12--END OF MOVEMENT [220 mm.]

Viola Version
NOTE: This outline includes all timings from the recording with viola that correspond to the measure numbers as given in the guide above for the clarinet recording.  It is abbreviated, mainly pointing out the discrepancies between the viola and clarinet parts.  The piano part is identical to the clarinet version.
1st Movement: Allegro appassionato (Sonata-Allegro form). F MINOR, 3/4 time.

0:00 [m. 1]--Piano introduction.
0:09 [m. 5]--Theme 1.  For the entire first phrase, the viola is an octave lower than the clarinet, creating a somewhat darker sound.
0:20 [m. 12]--In the continuation of theme 1 with the dotted rhythms in the piano, the viola moves up to the high octave, matching the clarinet part.  The lines reach too low for the viola to remain an octave lower.
0:42 [m. 25]--Transition, part 1, with triplet rhythms and arpeggios.  The viola again moves to the lower octave, below where the clarinet plays.  Also, the orientation of the notes in the two ascending arpeggios is altered.
0:53 [m. 33]--In this motion to D-flat, the viola remains in the lower octave, and the arpeggios are not changed.  Here, advantage is taken of the viola’s low C, a note the clarinet does not have (lowest note of the B-flat clarinet is the D a step above it).
1:03 [m. 38]--Transition, part 2.  Lyrical theme in D-flat major.  The viola moves back up to the original high octave used by the clarinet.  This is necessary to accommodate the very low notes at the end.
1:32 [m. 53]--Theme 2 (C minor).  In this first portion of the theme, the clarinet was in its lowest register at the beginning.  The viola thus continues to match the original clarinet notes.
1:45 [m. 61]--The viola easily transitions to the lower octave for the imitation, removing the shrill effect of the clarinet entry here.  It also begins with a grace note still another octave down, a technique typical of string instruments to add force to a gesture.  The rhythm of the swirling arpeggios in the viola is simplified from that seen in the clarinet part, and in fact matches that of the recapitulation, removing the irregular groups of five and seven on the upbeats in favor of more conventional groups of six.  The register is also closer to the clarinet recapitulation.  The first arpeggio is in the low octave, the second shoots up to the higher one (matching the clarinet), and the third again moves to the low octave.  Here, the last arpeggio again takes advantage of the low viola C.
1:58 [m. 68]--The viola imitations of the top notes of the piano arpeggios shift back up to the high octave used by the clarinet.
2:05 [m. 72]--In the “sighing” broken thirds, with the viola leading the imitation, the original register continues to be used (note that the clarinet reaches its lowest register at the end of the passage, as does the viola).
2:14 [m. 77]--Closing section.  Brahms very effectively brings the viola down to the lower octave here on its descents (somewhat matching the clarinet in the recapitulation).  He adds a rolled chord, notated in grace notes, leading up to the first note of the descent that pauses on the second beat.  This gesture is extremely typical and idiomatic for string instruments and here, it begins with the low viola C.  In the cadence gesture that follows, the low octave again allows the viola to take advantage of its rich low C.  This occurs as the piano begins its second forceful upward surge.  The following viola figures remain in the low octave while the piano makes its treacherous leap.
2:29 [m. 86]--Again, the viola descent pausing on the second beat is in the low octave and preceded by a rolled chord notated in grace notes (and beginning with the low C).  On the second note of m. 87, the viola makes a huge leap, shifting up to the high octave for the final cadence notes of the exposition (including the last isolated middle C’s) and matching the clarinet.
2:37 [m. 90]--Lyrical theme in A-flat major.  The initial viola responses in its first four bars (mm. 92-95) are an octave lower than the clarinet part.  This differs from the D-flat theme in the exposition, where they were at the same level.  The remaining four bars (mm. 96-99), already at the low end of the range for both instruments, obviously match the clarinet version with a much smaller leap down to the initial low note (E-flat).
2:57 [m. 100]--In this continuation of the lyrical mood in E major, moving to C-sharp minor, the viola part matches the clarinet part.  This is an extended high range for the instrument, notated in the treble clef rather than the alto clef for an unusually long period.
3:27 [m. 116]--Passionate transformation of lyrical theme in C-sharp minor.  The viola remains in the higher octave.
3:34 [m. 120]--Passionate version of Theme 2 in C-sharp minor.  The two viola imitations are both in the lower octave.  The clarinet jumped with the piano to the higher octave on the second one.  Brahms also adds a rolled chord to the first note of this second imitation in the viola.  The viola entry at the motion to F-sharp minor is also an octave lower than the clarinet.
3:52 [m. 130]--Climax and return of introduction in F-sharp minor.  The syncopated viola octaves at the beginning remain in the lower octave, continuing from the previous passage.  The last of these is a low C-sharp, the other viola note unavailable to the B-flat clarinet (again, its lowest pitch is the D).  In the more subdued re-transition approaching the recapitulation, the viola notes match those of the clarinet.
4:08 [m. 138]--Theme 1.  Unlike the clarinet, which here sounded an octave lower than the first presentation, the viola is in the same register here as it was there.  Of course, this means that it is in the same octave as the clarinet at this point.  Like the clarinet, the viola uses the ascending triplet arpeggios to move to the high octave (where it had not been in the exposition).  These triplet arpeggios are altered to reach less high than they do in the clarinet.  Presumably this was done for ease of execution on the viola, but the alterations avoid the leaps up to the original thematic notes on the last pitches of the arpeggios, which is somewhat unfortunate.
4:20 [m. 145]--This is one of the most distinctive alterations for the viola in the two sonatas.  The piano still has most of the interest, with the dotted rhythms and dissonant diminished seventh chords, but the dynamic two-note descents in the clarinet are made even more dramatic for the viola.  The first short figure, consisting of two leaps down a diminished seventh (minor sixth), is brought down an octave.  After that, the longer lines of two-note descents are brought back up, but the first note of each is made into a double stop.  The double stops combine the original clarinet notes for the most part.  The lower note of each figure becomes a “pedal” note, not in the original clarinet part, but fitting the harmony (first D, then G).  In the second set of double stops, the pedal G simply brings the already repeated G of the clarinet down an octave.  All of this makes this new, abbreviated transition more effective on the viola.
4:34 [m. 153]--Transition theme (Transition Part 2).  The presentation of the theme in F major remains in the higher octave in the viola.  This was already in the instrument’s high range on its first presentation in D-flat, and it now reaches to the highest note thus far (high C) in the viola part.
5:03 [m. 168]--Theme 2.  After the first piano bars, the viola enters, maintaining the same register as the clarinet.
5:16 [m. 176]--As in the exposition, the viola adds an octave grace note to the first entry of the imitation to lend it strength.  Unlike the exposition, the viola in this passage matches the clarinet, including the arpeggios.  Because of the changes to the viola part from the clarinet part at the analogous passage of the exposition (at 1:45 [m. 61]), with the shift to the lower octave, the music matches the exposition more closely here than in the clarinet version.  Only the very last note is shifted down the octave, with the viola leaping down instead of up.  Presumably this is because the viola is an octave lower in the following canon.
5:29 [m. 183]--In the canon with the intensified piano part, the viola is moved down to the lower octave.  The original register would have brought the viola to an uncomfortably high level.  The instrument has been unusually high through much of the recapitulation, but perhaps Brahms felt that this was too high, so he brought it down.  Unfortunately, the lower octave obscures the canon.
5:36 [m. 187]--The low octave is retained for the first two bars of the imitation on the “sighing” broken thirds, but it must be shifted up in the third bar, the upward leap in the descending sequence causing another disruption of the canon.  The jump is necessary because continuing in the low octave would reach below the range of the viola at the end of the descent.
5:44 [m. 192]--Closing section.  The clarinet was already lower here than in the exposition, and the viola matches it, adding a rolled upbeat before the first forceful descent that pauses on the second beat.  This upbeat consists of the notes one and two octaves below the first G of the descent.  At the point where the viola “saves” the piano from the treacherous descent (after its second upward surge), Brahms adds another wrinkle by keeping the viola in the low octave where the clarinet had gone back to the high one.  Again, this allows the viola to take advantage of its low C, which it uses at the end of the powerful descent.  This descent is also preceded by a rolled chord.  The cadence gesture that follows remains an octave lower than the corresponding clarinet part.
5:59 [m. 201]--The last viola descent moves back up to the high octave of the clarinet, and is preceded by a grace note an octave below.  The piano then makes its transition to the coda with the dramatic transformation of the first notes from the main theme.
6:09 [m. 206]--The mournful return of the main theme, its unexpected transformation to major, and the following B-flat-minor elaboration of the triplet figures passed between viola and piano, are all in the same octave register as the clarinet except for the last three notes of the last triplet figure.  These are changed from B-flat--A--G  to G--F--D, which helps transition to the lower octave, where the viola will play the following “sostenuto” passage.
6:26 [m. 214]--At the melancholy reverie marked “sostenuto ed espressivo,” Brahms takes advantage of the warm lower register of the viola by taking its part down an octave from the clarinet.  For this effect, he sacrifices having the viola play the oft-repeated note C in the same octave as the piano (as the clarinet does).
6:42 [m. 219]--In the varied repetition, expansion, and intensification of the “sostenuto” phrase, Brahms uses a repeated C in the second measure (m. 220) to move the viola back up to the original higher register with a simple octave leap.  At the climax, the viola again reaches a high C, its highest note in the movement.  It remains in the original high octave until it breaks off and the piano trails away.
7:09 [m. 227]--Version of four-bar introduction, sotto voce, in the piano.
7:20 [m. 231]--The first two bars of the original introduction and the reiterations of the note C in the viola remain in the original high octave to close the movement.
7:45--END OF MOVEMENT [236 mm.]

2nd Movement: Andante un poco Adagio (Ternary form with varied return).  A-FLAT MAJOR, 2/4 time.
This movement fits the string instrument sound and the viola range well, and Brahms did not make any changes in the viola part from the clarinet part.  There are no changes of register, direction, or rhythm.
A Section
0:00 [m. 1]--Main theme, first four bars.
0:17 [m. 5]--Continuation of the main theme with motion to E-flat and “deceptive” cadence.
0:48 [m. 13]--Restatement of the main theme without motion to E-flat.
1:03 [m. 17]--Abbreviated continuation of main theme with full cadence in A-flat.
B Section--D-flat major
1:28 [m. 23]--Lilting arpeggios in D-flat, then C-flat major.
1:42 [m. 27]--Chromatic arpeggios and motion to C-sharp/D-flat minor.
1:54 [m. 31]--Lilting arpeggios in the viola in D-flat, then in the lower octave in C-flat.
2:08 [m. 35]--Pattern similar to 1:42 [m. 27], with motion to E major.
2:27 [m. 41]--Main theme in E major in the piano with descents in the viola.  Diversion with triplet rhythm.
2:42 [m. 45]--Main theme in C major in the piano.  Diversion with triplet rhythm.
A’ Section
3:01 [m. 49]--Main theme in lower octave with triplet arpeggios in the piano.
3:20 [m. 53]--Continuation of main theme in lower octave, motion to E-flat, then back to A-flat.
3:54 [m. 61]--Statement of main theme in original octave with piano arpeggios in contrary motion.
4:12 [m. 65]--Abbreviated continuation of main theme with cadence and syncopated extension.
4:39 [m. 71]--Return of arpeggios from B section, then dissonant climax in the piano.
4:56 [m. 75]--Final statement of main theme with syncopated C’s in the viola and high descent of chromatic octaves in the piano.
5:41--END OF MOVEMENT [81 mm.]

3rd Movement: Allegretto grazioso  (Ternary form resembling a scherzo and trio).  A-FLAT MAJOR, 3/4 time.
A Section (“Scherzo”)
0:00 [m. 1]--Part 1.  Gentle Ländler beginning in E-flat, moving to A-flat.  Viola plays the melody in the same octave where the clarinet played it.
0:12 [m. 9]--Part 1, varied repeat.  The viola plays the clarinet figures without changes.
0:22 [m. 17]--Part 2.  Boisterous Ländler melody.  The low notes are very suited to the viola.
0:32 [m. 25]--Transitional bars.
0:37 [m. 29]--Return of melody from Part 1.  The viola part in the very first measure (m. 29) is altered from the clarinet, with an upward arching figure instead of an ascending one.  The second measure of the second phrase (m. 34) is brought down an octave to prevent an awkward leap on the viola.  A large, but smoother leap brings things to the original level in the next measure.  This is necessary for the two-bar extension with the shift back down to retain its effect.
0:49 [m. 39]--“Codetta” with the viola working upward and then the Ländler coming to a close.  First ending, m. 46a.
1:00 [m. 17]--Part 2 repeated.  Boisterous Ländler melody, as at 0:22.
1:10 [m. 25]--Transitional bars, as at 0:32.
1:15 [m. 29]--Return of melody from Part 1, as at 0:37.
1:27 [m. 39]--“Codetta,” as at 0:49.  Second ending, m. 46b.
B Section (“Trio”)--F minor
1:39 [m. 47]--Part 1.  Gentle, long piano descent with syncopated right hand.  The static low notes here are much more resonant on the viola than on the clarinet, which has a distinctively hollow tone in its low register.
1:49 [m. 55]--Part 1, varied repeat.  Viola absent for four bars, then re-enters.  The last measure moves to E-flat major.
2:01 [m. 63]--Part 2.  Soaring phrase in A-flat and E-flat, then emphatic motion to F minor.
2:22 [m. 79]--Closing phrase similar to Part 1.  Because of the long descent, Brahms does not shift the octave here, but the viola begins its line very high in its range.
2:35 [m. 63]--Part 2 repeated.  Soaring phrase and motion to F minor, as at 2:01.
2:57 [m. 79]--Closing phrase similar to Part 1, as at 2:22.
3:11 [m. 89]--Widely spaced low F’s in the piano, the second with fermata.
A’ Section (“Scherzo”)
3:17 [m. 91]--Part 1, as at the beginning.
3:27 [m. 99]--Part 1, varied repeat.  Similar to 0:12 [m. 9], but the piano plays without the viola and with wide left hand arpeggios.
3:38 [m. 107]--Part 2.  Boisterous Ländler melody, as at 0:22 and 1:00 [m. 17].
3:47 [m. 115]--Transitional bars, as at 0:32 and 1:10 [m. 25].
3:53 [m. 119]--Return of melody from Part 1, as at 0:37 and 1:15 [m. 29].  The two alterations from the clarinet part are still retained here.
4:06 [m. 129]--“Codetta,” as at 0:49 and 1:27 [m. 39], with “calando” marking at the piano entry.
4:24--END OF MOVEMENT [136 mm.]

4th Movement: Vivace (Rondo form).  F MAJOR, Cut time (2/2).
0:00 [m. 1]--Introduction, with fanfare-like intonation of three repeated F’s.  The viola entries on the upbeat flourish are both moved down an octave, still with the octave descent between them.  This takes advantage of the instrument’s low C, unavailable on the clarinet and here sustained before the beginning of the theme.
0:11 [m. 9]--Part 1 (a).  Grazioso rondo theme with light staccato answer, then motion to A minor.  The viola returns to the original higher octave.
0:21 [m. 17]--Part 2 (b).  Arpeggios moving from A minor back to F minor.  The viola follows the piano and slides back into the theme.
0:32 [m. 25]--Part 3 (a’).  Expansion of the main melody, merging into the tolling F’s and figures from the introduction.
0:46 [m. 36]--Transition.  Mostly played in the piano and based on material from the introduction.  The viola enters at the end with a descending arpeggio.
0:55 [m. 42]--Melody in triplets harmonized in sixths, with low tolling C’s in the bass.  The first two triplet leaps up two octaves in the viola are moved down an octave from the clarinet, again taking advantage of the low C.  After these first two bars, the viola moves to the original clarinet notes.
1:02 [m. 46]--Melody shifted up an octave, with two-octave leaps moved to the piano bass.  The viola line, which plays in harmony a third above the piano, remains in the high octave to keep the same effect, although this is quite high for an extended passage on the viola.  The copyist wished to transpose it down the octave, but Brahms corrected it back up.
1:09 [m. 50]--The soaring line in the viola also remains in the higher octave used by the clarinet.
1:15 [m. 54]--Light variation in straight rhythm, with imitations and octave shifts between piano and viola.  Then strong chords, also imitated between piano and viola, leading to a sustained “dominant” chord.
1:28 [m. 62]--Re-transition.  Repeated-note figure on C in the viola, followed by more figures from the introduction.
1:33 [m. 66]--Tolling repeated C’s an octave lower on the viola, followed by excited passage on the piano with two-note harmonies followed by higher single notes, bouncing around the keyboard.  The viola enters with its upbeat flourish in preparation for the theme, an octave lower than the clarinet, as at the beginning.
1:48 [m. 77]--Part 1 (a).  As at 0:11 [m. 9].
1:59 [m. 85]--Part 2 (b).  As at 0:21 [m. 17], but the viola does not play in the second phrase, and the passage is given completely to the piano.
2:11 [m. 93]--Part 3 (a’).  Similar to 0:32 [m. 25].  The viola and the piano right hand are reversed in the first two bars, then the piano takes the staccato bars alone with broken octaves.  The second bar of viola arpeggios is slightly altered to utilize the low C  The second phrase is as before, but comes to a complete close.
2:21 [m. 101]--Transition/Development.  Extroverted version of Part 2 (b) in the piano, moving from C major to A major.
2:26 [m. 105]--Viola enters with rondo theme in D minor.  Low tolling repeated notes on D.  Light staccato portion is transformed to heavy bass octaves.
2:31 [m. 109]--Continuation of theme in D minor with harmonization in thirds and sixths, and viola arpeggios in the low register.  Then trailing off of the theme and short-long figures passed between viola and piano.
2:47 [m. 119]--Semplice theme with dotted rhythms, first played by piano alone, then answered by the viola in the second phrase.
2:59 [m. 127]--Variation and decoration of the two phrases, with their presentation reversed and the viola presenting the first phrase.
3:10 [m. 135]--Beginning of third sequence, starting with viola presentation, converted into seven-bar transition with loud piano chords, sudden diminishing of volume, and motion to F major in extended cadence.
3:22 [m. 142]--The parts are re-arranged, with the viola playing low tolling F’s and the piano right hand playing the leaps up two octaves.  Analogous to 0:55 [m. 42].
3:29 [m. 146]--Analogous to 1:02 [m. 46], with the viola playing the groups of three tolling F’s an octave higher.
3:36 [m. 150]--Analogous to 1:09 [m. 50].  The piano plays the soaring line in broken octaves while the viola plays rocking figures, also in broken octaves and triplet rhythm.
3:43 [m. 154]--Analogous to 1:15 [m. 54].  The piano takes all of the variation in straight rhythm with a light touch.  The viola briefly enters in the passage that follows, which extends and intensifies the strong chords, leading to the descent of first-inversion chords.
3:55 [m. 163]--Re-transition.  Diversion to D-flat, with viola playing the three motto notes on that pitch, then pivot to A and back to F as the volume greatly diminishes.
4:14 [m. 174]--Introductory fanfare appears triumphantly in the viola, is extended with diversion to C major, then settles back down in F major in preparation for the varied rondo theme.
4:26 [m. 184]--Part 1 (a).  Variation of melody with light staccato character being applied to the whole first phrase.  Then heavy syncopated piano chords in imitation between the hands.  Viola settles music back down in the expected motion to A minor.
4:37 [m. 192]--Part 2 (b).  Arpeggios replaced by block harmonies.  At the end, the viola slides into Part 3 with the familiar extended upbeat notes, the piano also returning to the original form of the theme.
4:49 [m. 200]--Part 3 (a’).  Familiar version of the theme as heard at 0:32 [m. 25], up to the point where the cadence merges into the return of the repeated note motto.
4:58 [m. 207]--The repeated note motto expands into a brilliant coda based on the introduction material.  The viola trill and arpeggios are as in the clarinet version, as are the final notes and downward octave leap.
5:30--END OF MOVEMENT [220 mm.]