G-flat major Rondo-Finale of his Seventh Symphony. Mahler's Tenth Symphony was composed in the enharmonic key of F-sharp major. This key is more often found in piano music, as the use of all five black keys allows an easier conformity to the player's hands, despite the numerous flats. Austrian composer Franz Schubert chose this key for his third impromptu from his first collection of impromptus (1827). Polish composer Frédéric Chopin wrote two études in the key of G-flat major: Étude Op. 10, No. 5 "Black Key" and Étude Op. 25, No. 9 "Butterfly". French composer Claude Debussy used this key for one
D-flat major D-flat major D-flat major (or the key of D-flat) is a major scale based on D, consisting of the pitches D, E, F, G, A, B and C. It is enharmonically equivalent to C-sharp major. Its key signature has five flats. The D-flat major scale is: \override Score.TimeSignature #'stencil = ##f \relative c' { </score> Its relative minor is B-flat minor. Its parallel minor, D-flat minor, is usually replaced by C-sharp minor, since D-flat minor features a B in its key signature and C-sharp minor only has four sharps, making it rare for D-flat minor to be used. C-sharp major,