Franz Schubert's Piano Sonata in A minor, D 784 (posthumously published as Op. 143), is one of Schubert's major compositions for the piano. Schubert composed the work in February 1823, perhaps as a response to his illness the year before. It was however not published until 1839, eleven years after his death. It was given the opus number 143 and a dedication to Felix Mendelssohn by its publishers. The D 784 sonata, Schubert's last to be in three movements, is seen by many to herald a new era in Schubert's output for the piano, and to be a profound and sometimes almost obsessively tragic work.

Date of composition 1823
Type Sonata
Tonality A Minor
Catalogue D 784
Approx. duration 21 minutes
Instruments Piano
Autotranslations beta Franz Schubert: Sonate pour piano n°14 en la mineur, D 784
Franz Schubert: Sonata per pianoforte n. 14 in la minore, D 784
Franz Schubert: Sonate Nr. 14 für Klavier a-moll, D 784