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 the G pedal in the natural position, whereas there is no double-sharp position in which to put the F pedal for G-sharp major). Hector Berlioz called this key "majestic" in his 1856 "Grand Traité d'Instrumentation et d'Orchestration modernes", while having a much different opinion of its enharmonic counterpart. Despite this, when he came to orchestrate Carl Maria von Weber's piano piece "Invitation to the Dance" in 1841, he transposed it from D-flat to D major, to give the strings a more manageable key and to produce a brighter sound. Charles-Marie Widor considered D-flat major to be the best key for