Irrepressible Black plays Dewey Finn, a failed rock performer mooching on a friend, a substitute schoolteacher to whom he is substantially in debt for rent, and the friend's dominating, nasty girlfriend wants Finn to leave pronto. Intercepting a call, Finn pretends to be the teacher and grabs for himself a much-needed sub job at an upscale private school for himself. Finn is ignorant about virtually everything but rock, which he worships as a way of life. Before long he is secretly turning the class into a rock band instead of teaching the required subjects.

The students, at first perplexed, are amusingly adaptable, from the academically minded girl to the effeminate boy who adores making costumes. The talents of all are brought out by the imposter, who must hide his project from the uptight, by-the-rules principal, Ms. Mullins (delightfully played by Joan Cusack), who can be loosened by Black's maneuvering and a helpful quantity of beer.

One can predict the successful outcome despite the rage of parents when they get wind of Finn's scheme and his lack of teaching credentials. But "The School of Rock" is so much fun watching, and the youngsters so enjoyable that whether or not any of this is believable is beside the point. Mike White has written a script laced with unmissed opportunities for laughs. Black gives an outrageously entertaining performance in which his over-the-top acting becomes a plus. He is a very funny man and this is the perfect vehicle for him.