The members of silverchair can almost make you forget that they're not old enough to vote, by beer or get into most nightclubs if only they weren't the headlining act.

In an age when the sophomore slump is indiscriminate, the trio of 17-year-olds followed up its multi-platinum debut, Frogstomp, with a more varied and seasoned second album. Expanding its sound and song subjects for Freak Show, the Austrailian combo held onto enough of its old style while giving radio something that feels a little new and different. Acts twice their age should be so wily.

But if the members' youthful we-could-care less swagger doesn't bring the age issue back to the forefront, their schedule certanily serves as a reminder.

"I actually have got to go to school in 30 minutes,"drummer Ben Gillies said from his home in Austrailia."I'm sitting her in my school clothes ready to go."

Yes, the members of silverchair are still in high school, and,yes, many Austrailian high schools still require their students to wear uniforms. But the band is taking a break form its studies to tour North America (with a tutor in tow) and will stop at the Ogden Theatre Wednesday.

If they seem baby-faced now, you should have seen them three years ago. That's when the band of 14-year-olds sent a tape of it's first single, Tomorrow, to a television talent contest. Friends since kindergarden, Gillies,singer/guitarist Daniel Johns had been jamming with bassist Chris Joannau in Gillies' garage. Once they won the contest, they re-recorded Tomorrow and landed a record deal.

Twenty months later they each had more than $1 million tucked away in a trust fund and a debut album that sold more than 3 million copies. The quick trip from Austrailia's beaches to the Billboard charts did little to alter their work/study/play habits as the three prepared to record Freak Show.

"We wrote everything in my garage,"Gillies said."It is exactly like it was before. Someone would come up with a riff--I play a bit of the guitar as well--and then Daniel would write the lyrics. And then we'd sit down and write the music properly."

While Frogstomp took just nine days to record, the band took three weeks in the studio for Freak Show. That's a blink of the eye for most other bands, who can spend months making an album.

Musically, silverchair still sounds more like the Pacific Northwest than Down Under, mimicking a bit of the big guitar sond of Soundgarden on songs such as Slave and nicking Nirvana on tracks such as Learn to Hate and Lie to Me. But there's also more variety, with sweeping strings on the weep Cemetery and Zeppelinesque tabla and sitar on Petrol and Chlorine.

"We didn't really set out to write an album that had a lot of variety," the drummer said."It's just that we had been listening to a lot of different stuff, like Slint, a real mellow band , to Sepultura."

The lyrics on Freak Show also have a different bent. For its first album, the band had little life experience to mine for song subjects, so it instead wrote in response to what was on TV.

" The first album was stuff that wasn't really personal,"Gillies said. "This one was more personal, stuff that happened to Daniel and all three of us on the road, and the s--t we've had to put up with for the last 18 months."

Huh? Is this a teen-ager talking about rock'n'roll stardom as if it were already a burden?

"Sometimes, you just kind of get so sick of it you don't want to do it anymore," the drummer said."It's like ,'this isn't worth it. I'm only in it to play live.' Then in the end, if I didn't do all the bull, I wouldn't be able to travel around the world. It kind of makes it worth it in the end."

"We try not to whine too much. Nothing (angers) us more than big bands who complain about success. They could stop at any point. We're pretty well running the show now. If we wanted to, we could stop."

silverchair's not thinking about hanging it up just yet. For now, Gillies wistfully concedes he "won't get much surfing done this year,"while the band finishes its senior year of school and tours to support Freak Show.

But what will the members of silverchair be doing in 10 years from now, when the three are turning 27? Don't ask them; they're still too young to care.

"I really don't think about it," Gillies said."We might still be together, or one us might die or something. I don't really care what happens. You only live once. As long as I don't have to go sift through garbage bins, I'll be happy."