Outsider music: classics of American classical music (59) - Aaron Copland - Piano Variations (1930) Aaron Copland: Piano Variations (1930) After Ives, certainly the most important American composer ever, had various phases: the youthful/modernist phase, the mature and populist (in a good sense) phase, and the late phase in which he attempted to approach (timidly) dodecaphony. These Piano Variations are considered by many as a totem of 20th-century pianism and are part of the first phase of his career.