Form

sonata

Theme (B flat major)

Motive

Variation (F major)

Theme (F major)

Notes

The final movement restores the spritely dancing, the clear major tones of the triad, and a leaping, repetitive motive that bears great resemblance to material in the 1st movement. In fact, the 5 note trill motive from the 1st movement seems to return in more than one way. During the development, the new eighth note motive of this sonata permutes to a sort of slow motion parody of the trill. And in the final moments of the recapitulation, the original trill returns, a soft taunting whisper, eventually giving way to its brazen final form, an otherwise prosaic classical cadence in the final measures. This kinship between the spirit and the substance of the 1st and last movements is surely, once again, an aspect of Mozart's craftsmanship. There is coherence across movements through linkages that bind them together into an essential unity of the entire quartet.

The second key area begins with an energetic theme closely related to the first: it feels like a slight permutation of the latter's tail. They have common harmonic motions. This gives way to contrasting second theme, the more definitive arrival in the dominant key. It is a graceful dotted rhythm that sweeps upward and tumbles down in triplets, both rhythmic contrasts to the dominance of eighth note pulses in the prior themes. Once established, Mozart makes a return to the opening material (in the new dominant key) to round out the exposition. The leaping motive returns, as does a full statement of the first theme. The last few measures permute the leap into the trill, recalling the motive from the 1st movement. A dash of passing parody that will intensify once the development begins.

The development is based almost exclusively on the first theme. It appears at first that Mozart will launch into a tense fugato treatment of the theme, but this quickly subsides, returning to an augmentation of the theme, broadening the motion, then stiring it up again with a combination of the rapid three note descent from the second measure, and the oft mentioned trill modification. The recapitulation becomes the grand recaptiulation of the quartet itself, finishing with slightly more giddy enthusiasm that this light and playful quartet began.