At one point in time, Man of La Mancha was a very popular musical that was produced with frequency and with great reverence. Based on the book Don Quixote by Cervantes, the tale of the knight errant who travels an ugly and bleak world and refuses to see anything but optimism and beauty has been an inspiration to many. Man of La Mancha also includes a score that features one of theatre's most-beloved anthems of hope, "The Impossible Dream".