Etude in A flat,Op.25 No.1 'Aeolian Harp' Etude in A flat, op. 25 no. 1 Etude in G flat,Op.25 No.9 'Butterfly' Prelude in D flat,Op.28 No.15 'Raindrop' Etude in G flat,Op.10 No.5 'Black Keys' Prelude in D flat, op.28 no.15