Mozart’s Quartet K. 464: Part I
Introduction
Mozart’s Quartet in A major, K. 464 opens with an Allegro sonata form movement that is clear, elegant, and rich in counterpoint.
Exposition
The exposition opens with Theme Group A, which offers five separate statements of the same thematic material, each separated by silence.
We can break Theme Group A down into two distinct motifs: motif a1, a lovely descending legato line in the first violin, followed by motif a2, four punctuative short notes in all four voices. We first hear motif a1 and then immediately motif a2.
The first two statements of the theme follow this formulation: motif a1, motif a2, then silence.
The third and fourth statements are forte responses of a shortened version, or truncation, of motif a1.
The final statement is an extended version of motif a1 that concludes this opening with a surprisingly succinct amount of material presented in a clear and simple way.
From here, Mozart moves suddenly into the dark minor mode and proceeds to explore other key areas in quick succession. Mozart also introduces simple imitative counterpoint, in which each instrument successively takes up the a1 motif. This creates drama and a sense of conversation.
Next, Theme Group B contrasts with what we’ve already heard. Like Theme Group A, Theme Group B is also made up of two separate motifs: motif b1, a rising chromatic line, and motif b2, a twisting triplet figure.
Mozart then combines these two motifs (b1 & b2) in an elegant contrapuntal passage.
The Closing Theme Group does not introduce new material, but instead reuses material from Theme Group A which gives cohesion to the Exposition.
Now listen to the entire annotated exposition.
Development
In Mozart’s quartets, the development section is usually compact, but this development is nearly as long as the preceding Exposition. It contains material from both Theme Groups A & B, often mixed together in a variety of interesting ways.
Recapitulation
The recapitulation follows closely the same schema as the Exposition with the notable exception of the Closing Theme Group which is an extended development of the A material in imitative form.
This opening movement sets the stage for the rest of the quartet. Mozart will continue to explore an incredibly dense amount of counterpoint, but the music always remains clear, balanced, and elegant.