Making material shallower, even if cleverly, is not a great argument for adaptation. It can be defended if some other value is countervailing. For me, the show’s stagecraft and general high spirits come closest to providing that value, but they are too often undone by 1955-ish ideas of Broadway style (cartwheeling cheerleaders, backflipping jocks) and 1985-ish plot points held over from the movie.