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
Piano Sonata in E-flat major, D 568 (Schubert) Piano Sonata in E-flat major, D 568 (Schubert) The Piano Sonata in E-flat major 568 by Franz Schubert is a sonata for solo piano. It is a revision and completion of the Sonata in D-flat major D. 567. The D-flat major version was composed in June 1817, while the E-flat major revision and completion, published in 1829 after Schubert's death as Op. posth. 122, dates from sometime around 1826. I. Allegro moderato E-flat major II. Andante molto G minor III. Menuetto: Allegretto - Trio E-flat major IV. Allegro moderato E-flat major This sonata is a transposition and elaboration of the