Directed by Richard Linklater, starring Jack Black, Joey Gaydos Jr, Miranda Cosgrove, Kevin Alexander Clark, Robert Tsai, Maryam Hassan, Rebecca Brown, Joan Cusack, Mike White and Sarah Silverman.

It's a rare gift, but Jack Black is one of those comic actors who can hurdle a so-so script and make a film funnier just by being there. He was the best thing about 'High Fidelity', his wild-eyed stare put a bit more meat on the Farrelly brothers 'Shallow Hal' and his scenes with Colin Hanks in 'Orange County' made a throwaway comedy a little more memorable. In all of those movies, it was hard to see anyone else playing those roles, and so it is with 'School of Rock', Black's biggest star vehicle to date and a massive US hit - but a letdown.

All over the world there are men who made a teenage choice between records and a life and Dewey Finn (Black) is one of them. While pals grow up, settle down with people they really shouldn't be with and only pull their albums out for solo moments of nostalgia, Dewey is still rockin', harder and more ridiculously than any wannabe muso around. His onstage shapes, faces and stop-now guitar solos may seem like the height of cool to Dewey, but his bandmates don't think so and he's booted out, in favour of some guy with better hair and cheekbones so that they can win $20,000 in a battle of the bands.

Living with longtime buddy Ned (White) and control freak girlfriend Patty (Silverman), Dewey is warned (no prizes for guessing by who) that there is nothing going on but the rent and to find a job or get out. The career options for a man in his late twenties who has trouble dressing himself, but could probably list of all the Black Sabbath albums by order of merit, are few - until the hand of rock fate intervenes.

Ned is a substitute teacher and one day, while slacking, Dewey takes a call from the big wedge Horace Green Elementary School, looking for his flatmate to fill in for a few weeks. When he hears how much the money is, Dewey decides that he's going to be Ned, dusts off his dickey bow and does 'Stars in their Eyes' in reverse.

His new charges initially appear to be as starchy as their parents and Dewey's approach to being a teacher is the same one he had as a student: do nothing and watch the clock. But when he finds out the kids can all play instruments, Dewey decides to beat the boredom and turn them into a band that can wipe the floor with his former outfit. They've got the talent, he's got the heart  - and hopefully in a few weeks the $20,000.

Watching 'School of Rock' often feels like listening to your neighbour playing 'Smoke on the Water' on guitar through the wall: you hope something a little more demanding will be up next. This is one gag, stretched to 109 minutes and made all the more frustrating by the fact that the cast is so good - especially the kids, who make the film a cringe-free zone.

Throughout his career Linklater has looked at young people wandering around in adulthood trying to find out who they really are. 'School of Rock' needed a little more grown-up drama to really hit home - and the chance was there to work it into the comic stuff. As the tragically repressed school principal, Cusack is underused and both Linklater and White should've created some romantic angle between her and Dewey. There are hints that it could happen, but the music won't move out of the way and the film plays itself out very predictably.

As entertainment for kids, 'School of Rock' is cool enough for even the most jaded. Adults, however, could be disappointed. And guilt-ridden about never learning to play the guitar.

Harry Guerin