The first piano sonata that Beethoven published with an opus number is a piece that stamps the composer as an utterly unique creator who, despite all historical references, clearly distinguishes himself from his predecessors Haydn and Mozart. The slow movement is borrowed directly from the second movement of the Piano Quartet WoO 36 no. 3, which, in turn, is a reminiscence of Mozart's style. Above all, though, it is the two outer movements, surging dramatically forward, that show Beethoven's new path.