It’s 1957 and the musical avant-garde is in full swing. Pierre Boulez is dyna-miting the 19th-century furnishings. Karlheinz Stockhausen is wiring up the concert hall. John Cage has dispensed with sound itself. Benjamin Britten, meanwhile, withdraws to a house overlooking a golf course and offers the world Noye’s Fludde, a children’s opera whose only concession to modernity is the introduction of a row of tuned mugs as percussion.