When Northridge High School's 1975 graduates threw a 20-year reunion party in their Ohio township a few weekends ago, Robert Pollard behaved just as a burgeoning rock icon would. "I'm told I was a little belligerent," he says. And he got tossed out.

Pollard is the vocalist and prolific melody machine behind Guided by Voices (GBV). The late-blooming, free-swilling dervish, without airplay or MTV's blessing, has become alternative pop's unlikeliest idol. The stylistic scope of the band's catalogue makes categorization difficult, but, at its most accessible, GBV melds Mersey Beat melodies and grunge's gravity. Last year, just as the buzz about GBV was reaching a roar, the 38-year-old father of two quit school -- teaching fourth grade at Lincoln I.G. Magnet School in nearby Dayton, that is -- and made music his day job.

The midlife switch was just fine with the family. "Bob's never been happier, and it's great to see him get to do what he's wanted to do for such a long time," says Kim Pollard, who started dating Robert when he was the quarterback and she was a flag girl at Northridge High.

Pollard's age and sudden deification in a medium that generally doesn't allow late arrivals make him something of a musical Roy Hobbs: The aging protagonist of Malamud's "The Natural" comes out of nowhere to wow baseball fans with his otherworldly batting stroke. Pollard's gift for crafting pop hooks is so obvious that fans wonder why it's taken so long for him to get his shot in the big leagues. Beginning with this year's critically acclaimed "Alien Lanes," the band's first release on Matador Records, GBV is giving Pollard a chance to live out a rock-and-roll fantasy.

And he's bringing his best friends along on the ride. Guitarist Mitch Mitchell (Class of 1977) was pulling shifts at the local sandpaper factory before GBV became a touring band. Another Northridge alum, drummer Kevin Fennell, will rejoin the group as soon as he recuperates from back surgery. The newest member is erstwhile rock journalist Jim Greer, who, after declaring his love for Pollard's work in Spin, found himself replacing Greg Demos on bass. (GBV plays with Urge Overkill at the Capitol Ballroom tonight.)

Pollard's isn't an overnight success story. By the time "Alien Lanes" hit the bins, GBV had already put out seven LPs, not to mention scads of singles and EPs. And that's just what got pressed: Pollard estimates he's written more than 2,000 songs.

"I don't know how to describe Bob's writing," says Demos, the self-described Pete Best who left to pay off law school debts. "But I do know that he comes up with songs that grab me right away, songs that I want to listen to over and over. Listening to his music just makes me feel good."

Many of the earlier records, which were typically released by and for members and friends of the band, grew out of jam sessions that Pollard, Mitchell and guitarist Tobin Sprout periodically hosted at their homes. Using cheap recording devices, analog special effects and self-taught editing techniques, Pollard manipulated the basement tapes into collections of songs that sometimes averaged little more than a minute apiece. Then they'd print up a few hundred copies of each album on vinyl, give some away and keep the rest stored in boxes in Pollard's house.

"I wouldn't have minded at all if everything stayed the way it was," Pollard says. "I was having a blast just playing for fun."

But a number of people were determined to get GBV out of the basement. One was Vic Blankenship, who owns Trader Vic's Music Emporium, a record shop in Dayton. The two met in 1990, when Pollard began frequenting the store in search of obscure vinyl.

"For the longest time, I just knew Bob as a fourth-grade teacher and a great customer," recalls Blankenship. "But finally he told me that he had a band, too, and that they were called Guided by Voices. I told him, Are you the guys whose records are in the budget bins around town?' "

Without Pollard's knowledge, other band members were hand-delivering GBV albums to stores in Dayton and Columbus. "We were really worried that if we didn't do something, there was a good chance that nobody but us would ever hear Bob's music," explains Demos. The stores that took the records generally found that the supply, however small, exceeded demand.

That changed, but only after record store staffers persuaded Pollard to start playing clubs in Columbus. Then, Demos sent a copy of GBV's self-released "Propeller" to Scat Records, at the time a Cleveland-based indie label. "I was getting 100 singles a week and a few albums from new bands when I first heard from Guided by Voices," recalls Scat President Robert Griffin. "So I didn't even get a chance to listen to his album for several weeks after I got it. But when I did, it was all I listened to for months. I was totally taken."

Griffin quickly signed GBV, and within a week of that 1993 deal, Pollard had written, recorded and delivered a batch of six new songs for Scat to release. At Griffin's urging, the band did a showcase at the New Music Seminar in New York, and it won a slot on the career-making Lollapalooza tour. During the latter gigs, GBV's penchant for power-drinking caused tour mates to dub the band Guided by Beer. "I'm going to have to call it quits one of these days," Pollard says of his imbibing. "Or maybe just stick to watered-down domestic beer."

Whatever its basis, the exposure paid off. After GBV's "Bee Thousand" was released, Griffin turned over all of Scat's distribution chores to the much bigger Matador. "The band clearly required more resources than were at our disposal," Griffin says. "They were getting too popular for us."

Pollard is an avid reader of press clippings about his band, and gets a chuckle out of the genius tag so many critics have foisted on him. "It beats getting told the music sucks," he says. And Pollard has found a way to make a profit off the praise. A few weeks ago he took a pair of test pressings of early GBV albums into an Indianapolis record store and walked out with several hundred dollars. "I exploited the myth!" he laughs. "When people tell me they'll pay incredible amounts of money for my stuff, I tell them, I got boxes of it, man! I got more! I got more! Let me know!' "

At the recent Northridge High reunion, Robert Sheehan, Pollard's former football coach and a longtime guidance counselor at the school, talked with Kim Pollard about her husband's new career. Sheehan says his ex-quarterback's decision to give music a go reminds him of the gridiron grit he once displayed.

"My memories of Bobby are of what a tough kid he was," says Sheehan. "He never gave up. He kept plugging away. He got knocked down all the time. But he always got up. From what I hear about what he's doing now, I guess he's still got that same stick-to-it-iveness." Sheehan no longer coaches football, but he still doles out career advice to Northridge students -- including freshman Bryan Pollard, Bob's 14-year-old son. He's not encouraging him to follow in Dad's footsteps.

"Bobby was a great kid. I really liked him. But I didn't tell him to go into music," Sheehan says. "I never tell anybody to go into music." CAPTION: Robert Pollard, second from right, with his band, Guided by Voices.