For the Converted Only:

A Phenomenon Arrives

BY JON PARELES

Way back in the summer of 1991, Sonic Youth and Dinosaur Jr. were collegiate cult favorites while Nirvana, Gumball and Babes in Toyland were among dozens of largely unknown independent rock bands Just over a year later, Nirvana has sold four million albums teenage girls crowd Sonic Youth'; concerts and record companies are betting heavily ily on bands that would have been dis missed a year ago as just too noisy.

Sonic Youth and other bands toured European rock festivals for two weeks that summer, and Dave Markey's film "1991 The Year Punk Broke" documentary - their last season as insider idols. It also captures the raucous, disheveled, self-mocking, noncommittal and ironically triumphant alternative- rock pose. The music a squall, turning feedback and distortion into both assault and victory cry, sometimes tuneful sometimes lust a blare And the musicians work hard to proove, they don't take themselves too seriously. "Our audience is expanding, " says Thurston Moore if Sonic minds turning into a 'me gelatinoius ball 'of pepper.

The film. which opens today in New York, Chicago and Cincininati, and in other cities over the next two months. has all the regular ingredients of a tour documentary: shaky hand-held camerawork, backstage high links (Kim Gordon of Sonic Youth applies lipstick and mascara to Kurt Cobain of Nirvana). uncomprehending interviewers, wary tourism and unpolished live performances. But the principals have all "Seen Gimme Shelter" and "This Is Spinal Tap" and "Woodstock," and they know better than to appear too earnest. Musicians undercut themselves, knocking over equipment and fellow band members, turning backstage scenes into parodies of Madonna's "Truth or Dare." Mr. Markey's direction follows suit. breaking up razzledazzle performance montages with shots of a bratwurst vendor or a spinning beer bottle.

Still, those who wonder how Sonic Youth produces its huge clangor can glimpse, through the quick cuts and wayward pans the many ways the band abuses its' guitars. The film is for insiders; the bands don't try to endear themselvess, even to their own audiences. Yet there's no holding back the power of the music. which will give fans a pleasing jolt and grate mercilessly on others.