The compositions of American composer Charles Ives (1874–1954) are mostly modern classical music. Ives was prolific, revised works multiple times, and left ambiguous fragments with no title or notes. A chronology of works is especially difficult because of missing and sometimes misleading dates; as Elliott Carter put it in 1939: "[Ives] has rewritten his works so many times, adding dissonances and polyrhythms, that it is impossible to tell just at what date the works assumed the surprising form we know now."
