Chopin Etude Op.25 No.9 Butterfly Friedman Rec.1928

Chopin Etude Op.25 No.9 Butterfly Friedman Rec.1928

It sounds like Friedman is having great fun playing this etude. Paderewski also retards at 20,37 55 and 56. One would assume that this practice comes from Leschetizky.