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
Harmonic major scale which are also considered borrowed from the parallel minor: the minor subdominant, Dom 7 9, the supertonic diminished triad, the supertonic half-diminished seventh chord, and the fully diminished seventh leading tone chord. It also contains an augmented triad. The harmonic major scale has its own set of modes, separate from the harmonic minor, melodic minor, and major modes, depending on which note serves as the tonic. For example, a B major scale consists of the notes: B C D E F G A; whereas a B harmonic major scale consists of the notes: B C D E F G A.