“School of Rock” could easily end up being the biggest surprise of the fall – a comedy,… “School of Rock” could easily end up being the biggest surprise of the fall – a comedy, produced by a major studio, that’s hip, smart, irreverent and hilarious, while all the while family-friendly. And it’s the best showcase to date for madman-savant Jack Black.

If Black doesn’t rise to movie star status with this film, he never will. And that would suck. The actor – and rocker – hits home run after home run in this role, which was written expressly for him by Mike White (big, goofy comedies “Dead Man on Campus” and “Orange Country” and indie dramas “Chuck ‘ Buck” and “The Good Girl”).

White ingeniously gives J.B. a classroom full of kids as a forum in which to go nuts – the actor’s performance is far too volatile to have been entirely scripted – while inhabiting a persona that’s somewhere between the ferociously snobby music fan he played in “High Fidelity” and the obnoxiously cocksure “rock god” he becomes when rocking out with his band – really just he and Kyle Gass – Tenacious D. The maniac leaves so little oxygen for anyone else on screen that Joan Cusack’s performance is almost a casualty. Almost.

Black’s character is Dewey Finn, a deadbeat and rock music devotee who can’t even pay his roommate Ned (writer Mike White), an ex-rocker who sold out and is on his way to becoming a teacher, all the rent he owes unless his band wins an upcoming competition. After he’s kicked out of the band for his embarrassing antics, like 20-minute solos and drunken stage-diving, a chance phone call offers Dewey a way to earn the cash: posing as Ned for an extended subbing gig teaching fifth grade at an upscale private school.

The setup is silly and farfetched, but once the film gets rolling, you won’t mind a bit.

Dewey’s initial teaching approach is to make the students have recess all the time. That’s until he finds out that their intense music classes have made them skilled classical musicians. Dewey needs a band; they’ll be perfect if he can just teach them to rock. The School of Rock is born – under the guise of a class project, of course.

Two kinds of music are used brilliantly in the film. There are the rock classics, songs by AC/DC, the Who, the Ramones, Led Zeppelin and more, that place us in Dewey’s world. Then there is the music that we get to see created in the film. The child actors are the real thing – at age 10, they’re accomplished musicians. The sequences in which they and Black assemble and fine-tune songs – often in real time – are enormously exciting. Indie director Richard Linklater (“Dazed and Confused” and 2001’s “Tape” and “Waking Life”), who is selling out in a most glorious fashion, keeps these scenes, which are often lengthy and confined to the classroom, incredibly loose and lively. The result is magic.

“School of Rock” is the rare film that I feel comfortable recommending to absolutely anyone. It has the potential to be a huge hit at the box office – and it actually deserves to be.