アントン・シンドラー
Asked by Anton Schindler why the work has only two movements (this was unusual for a classical sonata but not unique among Beethoven's works for piano), the composer is said to have replied "I didn't have the time to write a third movement." However, according to Robert Greenberg, this may have just as easily been the composer's prickly personality shining through, since the balance between the two movements is such that it obviates the need for a third. Jeremy Denk points out that Beethoven "whittles away everything down to the absolute difference of the two movements", "an Allegro and an Adagio, two opposed poles", and suggests that "as with the greatest Beethoven pieces, the structure itself becomes a message".