Paul Green's Rock School was the real-life inspiration for the Jack Black movie "School of Rock." But Black's performance may seem muted, even quaint, compared to Green's behavior in the documentary "Rock School."

	Young guitarist plays in "Rock School." Click photo for larger image. "Rock School" Rating: R for language Starring: Paul Green, Will O'Connor Director: Don Argott "Rock School" Web site

He teases, threatens, bullies and belittles as a teaching aid.

He brings students to tears in f-word-spewing rants about how horrible they are.

"I will kill your family and bathe in their blood," he shouts.

"You mess up once, I'll punch your [bleeping] face in."

When it's time to mentally prepare his students -- who, it should be noted, range in age from 9 to 17 -- for a Black Sabbath tribute show, he shouts "Do you love Satan?" in one hapless student's face until he gets the uncomfortable "yes" he was after.

There are those who might have trouble with these methods. And Green is clearly a petulant, overgrown child who's living out his rock star fantasies through other people's children.

But it gets results.

From some kids anyway.

The movie follows Green and the cream of his musical crop to Germany for a triumphant climax at Zappanale, a tribute to one of Green's musical heroes, Frank Zappa, where they dazzle not only the seen-it-all crowd but Zappa sideman Napoleon Murphy Brock, who's proud to join them onstage for the complicated Zappa classic, "Inca Roads."

Even the students who don't necessarily learn much seem to really enjoy the experience of being bludgeoned with musical knowledge by a teacher who's more of a really old peer.

Will O'Connor, a student Green teases for wanting to kill himself, insists "If it wasn't for Rock School, I'd be dead. And I'm barely alive now."

Yeah, he's that depressing. But O'Connor is among the more compelling characters who share the spotlight in this documentary, a hard-luck story with a fondness for revealing embarrassing details of his life, such as "I had to sleep sitting up like The Elephant Man" and "I was misdiagnosed as retarded."

He may not be nearly as cute as the 9-year-old Tucker and Asa, twins whose mother paints their faces for the Sabbath tribute. But he's just as endearing.

Much like Green, who somehow emerges from this warts-and-all approach as charming despite all his tantrums and tirades and sociopathic behavior. You may leave "Rock School" wondering why a parent would subject a child to Green's abusive tactics. And you may have very real concerns for Green's own newborn. But you'll just as likely wish you had a teacher as hilarious, as prone to saying "[Expletive]!" and as in touch with what it's like to be a kid as Green so clearly is. He rocks.