C-sharp major
Most composers prefer to use the enharmonic equivalent D-flat major because it has just five flats. However, Johann Sebastian Bach actually chose C-sharp major for Prelude and Fugue No. 3 in both books of the Well-Tempered Clavier. In Hungarian Rhapsody No. 6, Franz Liszt changes key from D-flat major to C-sharp major near the beginning of the piece. Maurice Ravel used C-sharp major as the tonic key of Ondine from his piano suite Gaspard de la nuit.