Losing Autumn finds itself in a precarious position in the Diablo Valley College band room.

They get to play two songs to show what they've got to three critical, note-scribbling professionals in the front row, scrutinizing every note, look and riff. There will be no call for an encore, nor time for fan adulation. They finish to scattered applause from about a dozen fellow musicians, representing five young East Bay rock bands, then get called on the carpet.

They can't even hide behind their instruments. DVC music teacher Steve Sage tells the three young musicians to stow their gear and stand front and center. Guitarist Simon Taylor abruptly steps to the mic, shaking his head, unhappy with his playing.

"I don't know what I'm doing -- I'm sorry," he says to the front row. "I mean, I just got my cast off."

The room for sympathy is apparently down the hall.

"Never apologize," says professional musician and bandleader Carlos Reyes, kindly but firmly. "If you blow it, fake it. It's how you come out of it that matters. You are good," he pauses to smile. "Women want you. Men fear you."

That's the goal, anyway. The little joke works, relaxing the members of Losing Autumn, a pop-punk trio out of Moraga's Campolindo High School, while Sage, Reyes and local pro keyboardist Steve Roseman finish their assessments. Music is not an easy business, and they won't sugarcoat it for anyone.

It's a week before Sunvalley mall begins its "Battle of the Bands" competition, a four-week judged competition involving five local bands, resulting in the final two bands squaring off on Aug. 27. The five finalist bands were picked by a panel of judges in May. Each member of the winning band gets a $500 scholarship, which is nice but not why they're there.

What fuels the young musicians is what has motivated aspiring rock 'n' rollers since Elvis shook his pelvis to a screaming nation: love of music, the high of performing in front of a crowd, and the idea of becoming famous. If it all works out, the money would be nice, too.

But nobody's talking money in Sage's classroom. If they tried, Sage would probably tell them to quiet down and tune their instruments again. There's work to be done.

All five bands are here for a Battle of the Bands dress rehearsal and some last-minute critiques at the hand of Sage, who's acting as something of a rock mentor and adviser for the five bands, which have gone through a series of sometimes grueling sessions with Sage and his pair of guest music pros since the May tryouts.

Sage, a longtime teacher and touring guitarist, is an anomaly in both the world of teaching and of young garage bands. His classes at DVC force musicians to go beyond mere instruments when he has them form bands and play live before the semester ends. He's also a friend to younger bands, who can come take his classes at night and get college credit.

Well, maybe he doesn't always seem like their friend.

"I don't want to hear your problems," Sage says to members of the band Convergence, one of whom mentioned an amp problem before they started. "There's your amp. Plug in, shut up, play. "

It seems harsh, but it's no different than what a young rock band would hear from a veteran soundman at a busy club. These kids might as well hear it now, because if they pursue music as a career choice, they're going to hear it eventually, no matter how good they are.

"It hasn't got any easier, and I've been in Steve's class for two years," says Convergence drummer Anna Kremenliev, 18, of Walnut Creek. "It's hard because you know they're right. It's always hard when someone's being honest. When you first hear it, it's discouraging. But then I think 'I'm really lucky to have someone doing this.'"

When most young bands dream about making it big, they don't necessarily know about small or uncaring audiences. They don't contemplate equipment problems, or injuries, or being out of tune. They don't always know that they're not playing through the right amps.

But despite Sage's tough love, being in a young band still means having big, big dreams -- before bills, families and general reality force choices. It's about love of music and the ironclad belief that long odds don't exist.

If band members don't believe it, they never achieve it. These five bands -- Subcoma, Losing Autumn, Six Copper Sanity, Yours Truly and Convergence -- all possess the necessary faith and skill, which is why Sage works with them.

"We always say that we love performing," says Brian Bosen, singer and guitarist for Antioch's Subcoma. "But if we never performed again, we'd still play. The best thing about the professional help we're getting is that even if we don't win (Battle of the Bands), we may be discovered by an agent who likes us. So it's win-win."

"It's a way to get our feelings out," says Clark Abbott, guitarist for Yours Truly and an El Sobrante resident. "We love to do it and if we do get higher up the ladder and start selling CDs, it's the best job in the world. We'll do anything. We just want to get our name out there."

In an extreme example of having that necessary faith, Convergence lost band members at the beginning of the summer Battle of the Bands sessions, yet put together a completely new lineup just days before the dress rehearsal. Predictably they had problems, but nevertheless showed up and gritted out two songs after only one rehearsal together. No regrets.

"I can't see doing anything else," says Kremenliev, who nevertheless starts UC Berkeley in the fall. "It's always going to be music-related. I'm always going to play drums."

At this point in young careers, college can be a speed bump. Sage says he'd never discourage a musician from getting an education; he just wishes some bands would stay closer together.

Like Yours Truly, whose bassist Ronnie Renfrow is headed for college in Southern California on a full scholarship. Sage thinks the band, despite its youth, is ready to go pro now. The hooks are tight, the playing is strong, and the band understands stage presence. Yours Truly is the most advanced of the five bands, yet its members face a huge dilemma.

"I don't know what we're going to do about (Renfrow's departure)," Abbott says. "We either got to get another bassist, or figure something out."

That's another step in the learning process. There are always outside forces tugging at a band's cohesiveness. Members have to stick out their chins and keep going without losing momentum.

Though he has a year to go at Walnut Creek's Berean Christian High School, Clark Abbott's dad, Len, knows his son won't be making similar decisions anytime soon, because he simply knows his son. Not all parents are so understanding.

"Clark is not going to be an electrical engineer," Len says. "Music is a gift. You know the saying 'Your cards aren't worth anything unless you lay 'em down'? The world is open to him and I say 'Go for it.'"

That's exactly what they're doing. All of them.