High decibel

You think you are strong, strong enough not to laugh at anything silly. You think you can resist Jack Black, no matter what he throws at you, but the first lesson “School of Rock” teaches is that you can’t. He is that funny.

An amiable farce tailored specifically to the actor’s generous dimensions, “Rock” takes a clever premise and Black’s unflagging manic energy and comes up with a pleasing mainstream comedy that uses new people and attitudes to entertain in old-fashioned ways.

Knowing that opposites attract, especially inside-out opposites, “School of Rock” poses a pair of sharp questions: What if a rowdy rock musician taught at a strait-laced private school? More to the point, what if Black’s perpetually adolescent persona matched up against a roomful of actual young people who act like responsible adults? The result, which resembles “Mr. Holland’s Opus” on mind-altering drugs, always makes you smile.

Mike White is the writer behind “School of Rock,” and his idea here is much more audience-friendly than the smug, mocking notions that characterized his previous work on “Chuck & Buck” and “The Good Girl.”

Also, as someone who lived next door to Black for three years, White has intimate knowledge of the actor’s Energizer bunny rhythms, a style that led to his breakout role in “High Fidelity” and later parts in lesser films like “Shallow Hal” and “Saving Silverman.”

Here Black, who fronts a band called Tenacious D in real life, gets to play a guitarist named Dewey Finn who doesn’t let his questionable abilities and unlikely physique keep him from feeling like a god of rock ‘n’ roll.

No one has ever believed more in the music than Dewey. There’s no holding him back, not when he tears his shirt off and reveals a not-ready-for-prime-time body, not when he dives into the crowd and lands with a thud on the floor.

If thinking so could make you a star, Dewey would be in the firmament for sure. His band mates, however, aren’t entranced by his zeal and, intent on winning a local battle of the bands contest, they give Dewey the boot. Where he sees rock’s last angry man, they see, not to put too fine a point on it, “a fat, washed-up loser.”

Things are not much better on the home front, where Dewey has been freeloading for years off his nerdy substitute teacher pal Ned Schneebly (screenwriter White). But now Ned has a take-charge girlfriend (“Saturday Night Live’s” Sarah Silverman) who insists Dewey pay up or leave.

Shaken to his slacker bones, Dewey intercepts a call intended for Ned, puts on a bow tie and a “Dead Poets Society” scarf and takes a job subbing at prestigious Horace Green Prep. It’s a place where the students wear little uniforms and principal Rosalie Mullins (the always reliable Joan Cusack) is highly suspicious of Dewey’s teaching methods, which include a heavy emphasis on recess and lunch.

But one day Dewey hears his 10-year-old fifth-graders playing beautifully in the school orchestra and an idea is born: Why not turn them into a rock band good enough to enter that upcoming citywide battle? It could even be a school project, something that will “test your head and your mind and your brain, too.”

Naturally, there are problems. The project must be kept secret from downer parents and principal Mullins. Jobs must be found for class members who can’t play. Most daunting of all, this class of baby stockbrokers doesn’t have a clue about the music, about the way, in Dewey’s standard phrase, “one great rock show can save the world.”

Dewey plows through these would-be difficulties with the zeal of the true believer he is. Not only does his energy power the film, but it’s in the contrast between his wild and crazy exuberance and the timidity of students who believe they’re not cool enough to be in a band that director Richard Linklater (taking a major studio sabbatical after films like “Slacker” and “Dazed and Confused”) finds his humor.

Selected after the usual nationwide search for youngsters who knew how to make music, the kids in the class, even non-playing ones like the officious Summer (Miranda Cosgrove) are especially good. It is a little unsettling to see a film whose motto is “We Don’t Need No Education,” but the fact that the kids are learning to feel good about themselves does seem to help. Even if a great rock show can’t save the world, it can make for quite a funny movie.

*

‘School of Rock’

MPAA rating: PG-13, for some rude humor and drug references

Times guidelines: Crude at times but most of the humor is quite innocent

Jack Black...Dewey Finn

Joan Cusack...Rosalie Mullins

Mike White...Ned Schneebly

Sarah Silverman...Patty

A Scott Rudin production, released by Paramount Pictures. Director Richard Linklater. Producer Scott Rudin. Executive producers Steve Nicolaides, Scott Aversano. Screenplay Mike White. Cinematographer Rogier Stoffers. Editor Sandra Adair. Costumes Karen Patch. Music Craig Wedren. Production design Jeremy Conway. Art director Adam Scher. Set decorator Karin Wiesel Holmes. Running time: 1 hour, 50 minutes.

In general release.