G-flat major
Gustav Mahler was fond of using G-flat major in key passages of his symphonies. Examples include: the choral entry during the finale of his Second Symphony, during the first movement of his Third Symphony, the modulatory section of the Adagietto from his Fifth Symphony, and during the Rondo–Finale of his Seventh Symphony. Mahler's Tenth Symphony was composed in the enharmonic key of F-sharp major.