From the Movie Snob.

School of Rock. (A-) The potential for disaster was substantial. Would Jack Black take the edge off his obnoxious, rock-and-roll-obsessed, High Fidelity persona in a quest for greater mainstream appeal? Would the preppy kids at the hoity-toity school where Jack Black fakes his way into a substitute-teacher job turn in unbearably cutesy or cloying performances? Would the ending flame out in a saccharine display of new-found maturity (for Black) and liberation (for the kids)? The answer to all these questions, for the most part, is no. The potty-mouth and the sex-and-drugs aspect of rock and roll are undeniably tamed down, but the movie avoids all major pitfalls and had me laughing out loud throughout. Go see it.