The sonata is in three movements:
III. Allegro assai
From the Brilliant Set liner notes, p. 36:
In 1781 Mozart, at the age of 25, moved from Salzburg to Vienna and started his mature creative activities. This is one of his sonatas which are presumed to have been composed between 1781 and 1783, his first years in Vienna. The pleasant first subject, a graceful melody in 3/4 time, is followed by sudden “Mannheim rockets”, upwardly surging figurations. The innocent second subject in C major seems to try to calm down the disturbance. The development does not offer dramatic struggles, but gently introduces the second subject again, and after a building up of tension the soothing first melody sets everything apeace. The beautiful slow movement, with its tender aria‐like melody, lacks a more dramatic middle section, so as not to disturb the atmosphere of peaceful quietness and unclouded beauty of sound. The finale presents a whirlwind of sixteenth notes in 6/8 time. It presents a fine display of virtuosity, and its exhilarating momentum never fails to make a deep impression on the audience.
My first exposure to this Sonata was a Grigory Sokolov recording. I felt at the time I’d heard enough Mozart to last me forever, but it wasn’t so. I’m particularly taken with the “fp” passages in the first movement, like the one below, which you can hear starting at about 1:20 in the video. If I had technical training, I could no doubt tell you why, as it has not only to do with the quick shifts in dynamics and the rhythm, but also the harmonic sequence.
Credits: The sources for the quotations are as indicated in the post. The photographs, as always on the blog unless otherwise indicated, are mine.