When his band throws him out, Dewey masquerades as his supply teacher mate, Ned (Mike White), at a posh prep, where he lies to the kids, the head (Joan Cusack) and anyone else who might prevent him turning the tenyearolds into rockers and beating his former colleagues at the big gig: Battle Of The Bands. White, who wrote Chuck & Buck and The Good Girl, is good at skewing the everyday just enough for compelling weirdness, which may be why this is a two-joke film that only milks one of its jokes. Small people blasting it to The Man (Dewey's term for anyone in authority) is funny, but an anti-authoritarian who uses his position of authority to turn his charges into rebels would also have been a great joke if White had made anything of it, or if Black were more likeable.