Mozart completed his Piano Sonata in C minor, K. 457, in Vienna on October 14, 1784, according to his own catalog of his works. The following year he published it together with the Fantasia in C minor, K. 475—a brooding, improvisatory work completed in May 1785—dedicating the pair to Theresia von Trattner, one of his piano students and the second wife of prominent publisher Thomas von Trattner, Mozart’s landlord at the time. Opinions differ as to whether Mozart intended the Fantasia as an extended prelude to the Sonata; Mozart sometimes performed the pieces separately.

The C minor Sonata stands apart from Mozart’s other piano sonatas in its dramatic intensity and emotional gravity—its key was one he reserved for music of expressive weight. The outer movements present a stormy character that famously anticipates Beethoven—the young Beethoven knew the work well, and echoes of its opening gesture can be heard in his own First Piano Sonata in F minor, op. 2, no. 1.

Mozart’s opening commands attention with a forceful unison theme that rockets upward before dissolving into a chromatic dialogue. The lyrical second theme provides contrast, but the movement’s turbulent energy predominates.

The slow second movement with its searching character and expansive treatment is thought to have been composed separately, possibly as a teaching piece for Theresia. Mozart treats its tender melody with rich, varied embellishments each time it returns. The warm middle section no doubt inspired Beethoven in the slow movement of his Pathétique Sonata, op. 13.

The finale returns to the restless world of the first movement, with no hint of the merry sort of closing movement Mozart typically favored in his sonatas. Its driven figuration combines quick sighing figures, syncopations, dissonant suspensions, rhetorical pauses, and dramatic hand crossings for a masterfully tragic-sounding conclusion to the Sonata.

—©Jane Vial Jaffe