Unlike Beethoven's other C minor sonata-form movements, the exposition of this movement moves to the submediant (A major), not to the mediant, as its second key area. The quiet second theme bears a resemblance to the second theme in the final movement of the fourteenth piano sonata, made even more explicit in the recapitulation where this theme is restated ominously in the bass in minor mode, after initially appearing in C major. Overall, the first movement contains motivic similarities with Mozart's Adagio and Fugue in C minor, which Beethoven arranged for a string quartet (Hess 37).