He began composing in his early years in a late romantic style, but after 1907, when he published his "Sketch of a New Esthetic of Music", he developed a more individual style, often with elements of atonality. His visits to America led to interest in North American indigenous tribal melodies which were reflected in some of his works. His compositions include works for piano, among them a monumental Piano Concerto, and transcriptions of the works of others, notably Johann Sebastian Bach (published as the Bach-Busoni Editions). He also wrote chamber music, vocal and orchestral works, and operas—one of which, "Doktor Faust", he left unfinished when he died, in Berlin, at the age of 58.