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
A-flat major passages or movements in the key often retained the timpani settings of the preceding movement. For example, Beethoven's Symphony No. 5 in C minor has the timpani set to C and G for the first movement. With hand-tuned timpani, there is no time to re-tune the timpani to A-flat and E-flat for the slow second movement in A-flat; accordingly, the timpani in this movement are reserved for the passages in C major. In Bruckner's Symphony No. 1 in C minor, however, the timpani are re-tuned between the first movement in C minor and the following in A-flat major. Charles-Marie Widor