The Sonata for cello and piano no. 4 in C major, Op. 102 no. 1 was finished in 1815, simultaneously with the Sonata for cello and piano no. 5, and published in 1817 with dedication to Countess Marie von Erdődy, a close friend of Beethoven's. The complex and visionary character of this couple of sonatas marks the definitive start of Beethoven's so called 'third period'. Sonata no. 4 is a work in two movements: short and almost enigmantic, it summarizes in concentrated for how Beethoven was preparing to subvert the sonata structures inherited from Haydn and Mozart. Its overall structure is possibly unique in Beethoven's works, comprising just a pair of fast sonata-form movements. Both movements recall the long-established convention of a slow introduction to a brisk main section, but with significant modifications.
