The work consists of the following four
movements : \relative c'' { \set Staff.midiInstrument = #"violin" \tempo "Allegro" \tempo 4 = 126 \key a \major \time 4/4 e2( cis | b a) | b4( cis d b) | gis2( a) | fis4( a e a) | e2 d4.(\startTrillSpan cis16\stopTrillSpan d) | cis4 }
II. Larghetto The second movement opens with a six-bar transition in place of a
central development section, which opposes a first section consisting mostly of a clarinet melody over
muted strings against a second group of themes in which – as in the first movement – several upward runs of scales are given to the first violin, alternating with brief phrases of clarinet melody. These scales are given to the clarinet in the
recapitulation (bar 51). In the last few bars of the movement, more
chromatic than the rest, the scales turn into
triplet arpeggios traded between the strings under the closing clarinet phrases.
III. Menuetto The third movement consists of a minuet and, unusually, two trios. The first trio is for the strings alone, with a theme that has a signature
acciaccatura every few notes. The second trio is a clarinet solo over the strings, whereas in the minuet the roles are distributed more evenly.
IV. Allegretto con variazioni The finale is in
variation form, unexpectedly substituting for the more conventional rondo. There are five variations. The theme is in two repeated halves, with the clarinet joining in, but only for a few of its bars. As often with Mozart, phrase structure is generally the same throughout the variations even if other qualities change – the theme consists of four four-bar phrases (Mozart is often more irregular in his phrasing than this), the first going harmonically from A to E, the second back from E to A, etc. and likewise with the variations. The first of its variations gives the clarinet a new theme, in
counterpoint with the theme of the variations divided amongst the quartet. The second alternates phrases for quartet only with phrases for full quintet, the latter answering the former. The third, in A minor, also begins without clarinet. It features a viola melody – also with signature
acciaccatura – sometimes described as sobbing. The clarinet joins in to finish. The
major mode returns for the fourth variation, as does the main theme to the accompaniment of
semiquaver virtuosity – given to the clarinet only in the first repeated half, first violin and clarinet in the second. There are four bars of dramatic interruption leading to a pause; the next variation is a lyrical Adagio. A transition leads to an Allegro
coda, containing much of a variation itself. : \relative c'' { \set Staff.midiInstrument = #"violin" \key a \major \time 2/2 \tempo "Allegretto con variazioni" \tempo 4 = 132 e4-.\p e-. cis-. cis-. d8. (e16 fis8. d16 ) b4-. b-. a-. a-. b-. b-. a4.\startTrillSpan (gis16 \stopTrillSpan a) gis2-! } == Analysis ==