Question: The Unanswered Question is a ballet made from work by a man who was regarded as what?
Sentence (from "The Unanswered Question (ballet)"): The Unanswered Question: Some Intimations of the American Composer Charles Ives is a ballet made by Eliot Feld to Charles Ives' "The Unanswered Question", "Calcium Light Night", "Fugue in Four Keys, Mists", "From the Housatonic at Stockbridge", "Sonata No. 2 for Piano and Violin (In the Barn)", "Remembrance" and "An Old Song Deranged".
Relevant evidence: Yes