The first landmarks of this mature style are the group of piano works published in 1907–1912 (the "Elegies", the suite "An die Jugend" and the first two piano sonatinas) and Busoni's first completed opera, "Die Brautwahl"; together with the rather different Bach homage, the 1910 "Fantasia contrappuntistica", Busoni's largest work for solo piano. About half an hour in length, it is essentially an extended fantasy on the final incomplete fugue from Bach's "The Art of Fugue". It uses several melodic figures found in Bach's work, most notably the B-A-C-H motif. Busoni revised the work a number of times and arranged it for two pianos.