School of Rock

If we've learnt anything from Fame Academy and Pop Idol, it's that while you might be able to teach someone how to be a cruise-ship crooner, you can't teach them how to be a rock star. But if anyone could do it, it would be Jack Black. He's the wild-eyed satyr currently best known for terrorising John Cusack's customers in High Fidelity, but who will soon be best known for a new family comedy, School of Rock.

He plays Dewey Finn, a slobby music obsessive so close to the one he played in High Fidelity that School of Rock could be a spin-off, updating us on what would have happened if the character had left the record shop and tried to make it as a rock star.

Unsurprisingly, he's still trying. His heavy metal band has been going nowhere for years, and his big-haired bandmates think that it might be his fault. Sick of being embarrassed by his twiddly guitar solos and his shirtless belly-flops into the audience, they kick him out, just a month before a prestigious Battle of the Bands contest might have propelled them to fame and fortune. He can make ends meet only by sleeping on the floor of his best friend, Ned Schneebly (Mike White), a bass player manqué who has woken up from his rock'n'roll dreams and taken up substitute teaching.

Although Dewey is in no hurry to join the rat race himself - "I service society by rockin'," he reasons - Schneebly's girlfriend wants him to pay rent or move out.

Dewey's solution is to pass himself off as his flatmate, and sign on for a few weeks' supply teaching at an exclusive prep school. He can't even spell Schneebly, or much else, but he has no problem with leaving a class of 10-year-olds to its own devices, rousing himself from his naps only to have a sandwich or to impart one or two rudimentary life lessons to his charges: "Can anyone tell me what 'hangover' means?"

Then he has an idea. He'll teach the best musicians in the class how to play one of his songs, and designate the remaining children as technical crew and groupies. ("They're like cheerleaders," he explains.) In three weeks he'll be able to enter Battle of the Bands with the kids as his backing group.

Anyone who has a justifiable fear of films with children in them should rest assured that there aren't any precocious stage-school moppets in the cast.

Black's juvenile co-stars are disarmingly unaffected, often laughing at their teacher's antics, probably because they were cast as much for their musical skills as for their thespian ones: they all play their own instruments. Besides, while the good-natured script hands out a distinct role to each child, so that younger viewers will be able to find at least one to identify with, none of them gets very much screen time. And Black excepted, nor does any of the adults.

Joan Cusack holds her own as the school's tightly wound headmistress, but Black appears in almost every second of the film, and he squeezes the comic potential out of all of them. Like all the great movie clowns, he can move with a fluid dexterity that would put most boy-band members to shame, but which becomes phenomenally funny when combined with the character's troll-like physique and his heroically ignorant faith in his own rock-god magnetism.

Black also radiates goofy guilelessness, even while being irresponsible and selfish: whatever he's doing, enthusiasm lights up his face. His spiritual forebear, John Belushi, demonstrated his mastery of the comically raised eyebrow in Animal House, but Black outdoes him with a Mexican Wave that travels across both eyebrows and back again.

The screenplay was custom-built for him by his friend and co-star, Mike White. (The weird yin-yang correspondence of the names Jack Black and Mike White is a mystery for another day. Maybe it's got something to do with why they set the movie in a school called Horace Green Elementary.) White has scripted a run of leftfield hits - Chuck & Buck, The Good Girl, Orange County - but it's still disorientating to see how easily he jumps from uncomfortable indie films to mainstream crowd-pleasing.

What's more disorientating is that School of Rock is directed by Richard Linklater, the maker of Slacker and Dazed and Confused. His last film, Tape, was shot on digital video in a motel room, and his film before that, Waking Life, was a psychedelic animated symposium, so it was inevitable that murmurs of "sell-out" would follow when he took on a film that could seem, on paper, to whiff of let's-do-the-show-right-here ickiness.

But School of Rock wouldn't be as irresistible as it is if it hadn't come from independent film-makers. For one thing, it wouldn't have the unfakeable love of Led Zeppelin and AC/DC that Black, White and Linklater bring to it. They worship rock'n'roll almost as devoutly as Dewey does, so his discourses on the guitarist's "power stance", the corrupting influence of MTV, and the keyboard solo on Yes's "Roundabout" always have the ring of truth. And that's what will ensure School of Rock's status, next to This is Spinal Tap, as essential tour-bus viewing for years to come.

But the full miraculousness of the film becomes apparent only when you tot up all the mistakes it doesn't make - all the traps it might have stumbled into if it had been yanked this way and that by test screenings and studio executives. This is no Dead Rock Stars Society. There is no rancorous rival teacher who vows to expose Dewey. There is no suggestion that the children were repressed and miserable until he turned their young lives around - they would have got along very nicely without him.

The film resists the temptation to plonk in a guest appearance from a superannuated rock star, and the suitably ass-kicking soundtrack doesn't feature a single bar of "School's Out" by Alice Cooper. Lastly, School of Rock is free of the two diseases that are blighting American comedy - gross-out humour and parodic winks at other films.

Having said that, every band has to play some of its greatest hits in concert, and there are scenes that this type of film can't do without: the one in which Black is confronted by the kids' parents, for one, and the triumphal gig at the end. But even these golden oldies can't spoil the fun.

The victorious finale isn't quite as victorious as it could be, while the showdown with the parents has any solemnity ripped from under its feet by one of the best punchlines of the movie - and of the decade.

School of Rock is the most consistently pleasurable Hollywood film I've seen in a long time. It has a lot to teach us about rock'n'roll, and even more to teach us about comedy.

n.barber@independent.co.uk