For America, though, his harmonies are a shade too sophisticated, his wit too introspective, his metaphors too clever by half. Those who go to a musical in expectation of a boy-girl plot and a hummable show-stopper feel cheated by Sondheim. At 72, he belongs less to the comfort line of Rodgers and Hammerstein than to the laconic selflacerations of Noël Coward and Frederick Ashton. He writes, somehow, in an English accent. I have never met him, but I'm sure he'd say tom-ah-to, not tom-ay-to.