Jack Black in "School of Rock"

Jack Black poses as a substitute teacher in "School of Rock" but can't hide his love for music. (October 2, 2003)

Jack Black and Mike White started their rock 'n' roll journeys from two very different places.

In fact, Black and White's musical roots are about as opposite as their surnames suggest.

The former, a dough-faced star known for his Farley-esque exuberance, impish persona and biting wit, spent his formative years sporting Sabbath T-shirts and kneeling to the dark lords of heavy metal.

The latter, a talented, mild-mannered screenwriter, grew up the milquetoast son of a Christian minister and trudged his way through a strict preparatory education on a steady -- albeit forced -- musical diet of white gospel and the Jesus Christ Superstar soundtrack.

If they hadn't lived next door to each other for years, the unlikely duo might not have crossed paths.

But as the rock gods would have it, in the late '90s, the struggling twentysomethings wound up as neighbors.

The pair quickly discovered that they were both drawn to the so-called devil's music -- Black because he was hungry for the rock idolatry that's reserved for crushing ax slingers, and White because he enjoyed being close to the pagan mayhem.

"I was like, 'I wanna rock! I wanna act; I wanna be in the arts,' " said Black, who, when he met White, was still searching for breakthrough roles and playing in the folk-metal/comedy duo Tenacious D.

White, on the other hand, had less riotous ways of displaying his proclivity for all things rock.

"I'm a closet rebel, just like I was in high school," he said.

The self-described "dork-on-a-fork" couldn't pull off a clutch guitar solo if he tried. But the "born scribbler" knew how to write about a guy who could.

In the new film School of Rock, the friends of circumstance pool their talents on and off screen to create a funny yet poignant story of the unifying power of rock 'n' roll.

White's tale of a loser turned hero opens tomorrow with Black starring as down-on-his-luck Dewey Finn, a hard-rockin' wannabe musician with a bad case of arrested development. In need of rent money, a desperate Finn poses as his substitute teacher roommate, Ned Schneebly (played by White), and is given a job as fill-in instructor for a class of fifth-grade prep-schoolers.

After throwing out the traditional curriculum, the impostor abuses his teacher status and uses the homeroom time to shake off hangovers while the kids run loose. But when Finn overhears his charges' orchestra rehearsal one day, he's electrified by their musical promise and begins to teach them a class he calls "rock band."

The strait-laced kids get a weeks-long lesson in rock, including a chalkboard diagrammed guide through the history of the genre and practical instruction in classic rocker moves (think windmills a la Pete Townshend and Tommy Lee stick twirls).

And in the process, Finn discovers both his knack for teaching and a circuitous route to a coveted spot in the local battle of the bands.

The story, White says, was written with his longtime friend in mind.

"I sort of feel bonded to him. [The script] was a valentine to my respect for him," he said.

So much, in fact, that the 33-year-old writer said the film could be made only if Black would assume the lead character.