Beethoven is the first composer to represent the complex process of memory-not merely the sense of loss and regret that accompanies visions of the pa… - Charles Rosen

None of Chopin's contemporaries could rival him for the variety and effectiveness of his treatment of the return.

Only once in Chopin's music is there a direct reference to Bach, and that is, appropriately, at the beginning of his only educational work, the two sets of Etudes, Op. 10 and 25, and the three Nouvelles Etudes for Moscheles. In the first Etude, Op. 10, in C major, we find a modernized version of the Prelude no. 1 of the Well-Tempered Keyboard...

I do not think that any composer has ever asked for octave glissandi on the black keys, but there is a recording by Moriz Rosenthal of Chopin's Black-Key Etude in which he plays the short octave passage in both hands glissando: it hurts my hands just to think about it.