The model here is Mozart's G major Sonata K.379: both works begin with an Adagio too substantial to function as a mere slow introduction, yet at the same time deliberately designed to lack the effect of a self-contained movement. Both pieces are in sonata form, though they break off before the recapitulation can get under way. Instead, there is a dramatic Allegro in the tonic minor (in the Beethoven, Eb minor). The main theme of this Eb minor section was inspired more by the Sturm und Drang style of C.P.E Bach than by Mozart and was originally sketched out in C minor, as the start of a symphony in that key. The exposition's chromatic closing theme was to find its way into another C minor work, the Piano Trio Op.l No.3. It is symptomatic of this dramatic piece, with its explosive coda, that the exposition remains in the minor throughout. The variation finale follows closely the plan of its Mozartian model, with a first variation in smooth semiquavers, and a second transforming the theme into semiquaver triplets on the violin. As in the Mozart, there is also a march-like variation in the minor, in dotted rhythm.
1. Adagio assai (attaca)
2. Allegro con spirito
3. Theme: Cantabile. Variations 1-6.Theme: Allegretto