Aren't twin children cute? Especially when one of them wears a Mohawk and the other has "O-Z-Z-Y" written on his knuckles, and they team up for a duet on Black Sabbath's "Iron Man?" Pre-teen head-bangers Asa and Tucker Collins certainly put most leotard-wearing, carol-singing "normal" kids to shame. But then again, they've had lessons at Rock School. This engaging 2005 documentary not to be confused with the Jack Black comedy School of Rock profiles Paul Green, the intense, possibly deranged founder and head of the Paul Green School of Rock in Philadelphia, where kids from nine to seventeen learn the baser points of keeping rhythm and the finer points of complex chord progressions. Green's pedagogical style is one-third Dead Poets Society and two-thirds Full Metal Jacket, and he doesn't seem capable of censoring himself in front of director Don Argott's camera. He lays into his students with profanity-laced tirades, sometimes seeming a hair's breadth from slapping them around, as redolent of tough love as the most excitable high school football coach. The thing is, it works for at least some of the kids. Rock School gets to know a few of Green's charges, each a fascinating case. There's C.J. Tywoniak, a soft-spoken guitar wizard who mimics Eddie Van Halen solos note for note; the aforementioned Collins twins, whose mother supports their heavy metal dreams as avidly as any soccer mom; Madi Diaz-Svalgard, a talented voice with a Quaker rap music skeleton in her closet; and then there's Will O'Connor. Will volunteers almost too readily what a troubled childhood he's had, and he admits to repeated suicide attempts. He's a self-described social misfit, but he's also the most eloquent person in the film and the only one who seems to really "get" Paul Green (Green included). If there's anyone for whom Rock School could be a dramatic, life-changing experience, it's Will. Giving the film its narrative structure is an invitation to play at "Zappanale," an annual Frank Zappa festival held in Germany. Green's advanced students treat Zappa's music, appropriately, as just about the most difficult rock to play, and the challenge of mastering it in front of Zappa fanatics who worship every note seems almost too much. The result is genuine suspense, and a group of kids who will stay with you past the closing credits. Sony/Columbia TriStar's DVD release of Rock School includes a commentary from Argott, producer Sheena Joyce, and editor Demian Fenton. Fenton's participation is especially welcome, considering how vital the editing process is to a documentary like this, where the primary creative task is creating order out of hundreds of hours of footage. The filmmakers lay out the rules for "Rock School: The Drinking Game" and discuss how they learned of Madi's Quaker rap past only toward the end of filming. (The scenes with her group, The Friendly Gangstaz, are priceless.) A movie like this, with so much performance footage and such a voluble main character, cries out for deleted scenes, and the disc provides over 45 minutes of them, most of which are as entertaining as those left in. The anamorphic transfer (1.78:1) accurately captures the digital-video look of the film. It would have been fun to have the soundtrack remastered in a 5.1 variant, but the Dolby 2.0 Stereo presented here is far more true to the performances captured. Keep-case.