The Piano Sonata in A minor, 537, of Franz Schubert is a sonata for solo piano, composed in March 1817.
I. Allegro ma non troppo
A minor. In sonata form. The exposition modulates to the submediant, F major, rather than to the usual mediant, C major. The recapitulation begins in the subdominant, D minor, and most of the recapitulation's second group is in A major before a short coda returns to the minor mode for the movement's ending.
II. Allegretto quasi andantino
E major. A five-part rondo with an unconventional key scheme as follows:
A (E major) → B (C major) → A (F major) → C (D minor) → A (E major)
Schubert also composes brief transitions at the ends of each episode—that between the B section and the medial A section features a small amount of the B section's material in F major (the medial A section's key), while that between the C section and the final A section modulates from the C section's D minor up a tone to E minor, and then sits on its dominant for a few measures before the return to the movement's tonic key with the final A section. The movement ends with a short coda that is completely diatonic.
III. Allegro vivace
A minor. In sonata form without development. The exposition begins with A minor and modulates to E major. The recapitulation begins in E minor and moves to A major, in which the movement ends.[1]
The work takes approximately 20 minutes to perform. Daniel Coren has summarised the nature of the recapitulation in the last movement of this sonata.[2] Harald Krebs has noted that Schubert reworked the opening of the second movement of the D. 537 sonata into the opening theme of the finale of the A major piano sonata, D. 959.[3]
The piano sonata is featured in the 1985 film adaptation of E. M. Forster's A Room with a View, as protagonist Lucy Honeychurch is practicing piano.