The Sonata for Arpeggione and Piano in A minor, D. 821, was written by Franz Schubert in Vienna in November 1824.

The sonata is the only substantial composition extant today for the arpeggione (which was essentially a bowed guitar).

The piece was probably commissioned by Schubert's friend Vincenz Schuster, who was a virtuoso of the arpeggione, an instrument which had been invented only the previous year.

By the time the sonata was published posthumously in 1871, the enthusiasm for the novelty of the arpeggione had long since vanished, together with the instrument itself.

Transcribers have attempted to address the problems posed by the smaller playing range of these alternative instruments, in comparison with the arpeggione, as well as the attendant modifications in articulation (4 versus 6 strings).