In the Tuesday, Sept, 20, finale of CBS' "Rock Star: INXS," the members of the Australian rock band will pick a new lead singer from among the final four members of a talent pool that numbered 15 at the show's premiere on July 11. That person will take the place of Michael Hutchence, who died in 1997.

For surviving contestants Mig Ayesa, Marty Casey, J.D. Fortune and Suzie McNeil, it's been a long, strange trip. Each has had years of professional experience, but the whirl of filming, performing, publicity and workshops conducted by INXS and others has pushed them to -- and even beyond -- their limits.

"This is definitely rock 'n' roll boot camp," says the lanky blond Casey, taking a break in the billiard room of the "Rock Star" mansion before performing in an acoustic jam session after the taping of the Tuesday, Sept. 13, episode.

"I really have changed. Number one, confidence in what I'm doing, even songwriting-wise. It's going from shoving your songs down people's throats, 'Listen to me,' to just doing a song once in the right place, and having people love it.

"This is the experience of 10 years on the road without actually having done it. There's plenty of partying, but all that aside, what it's been about is the pressures of uncertainty.

"Now, if they say, 'You have to hang upside down and sing this song, and we want you to do it in reverse,' I'm like, 'Fine. I can do that.' I've done it all. There really is nothing I can't do now."

Along with the exposure and the opportunity to take on fear by conquering new challenges, the contestants have also had the benefit of weeks of comments and instruction from the members of a band that has survived for 20-plus years in the music business.

"INXS has been around for a long time," Casey says. "They have a lot of wisdom. They've been up; they've been down. They've been giving me advice, like, 'We worked with one of the best frontmen ever, so why don't you try cooling it down a little bit?' So I tried it one week; it really worked. 'Why don't you try screaming less, and saving that potent scream for the moment you need it?' 'OK, you know what, I won't scream all through the song, I'll sing it, and I'll scream just at one point.' It really works; it's effective.

"So those are the tools that I've learned, and getting this falsetto voice that I never knew I had. There have been a few honest musical breakthrough moments that kicked me up a notch."

While INXS has been advising and judging these hopefuls, the band members -- Kirk Pengilly, Garry Beers, and brothers Tim, Andrew and Jon Farriss -- also know they're seeking a permanent replacement for a man who was a friend and colleague for more than two decades.

In collaboration with Hutchence, Andrew Farriss -- who describes himself as "resclusive" and "an introvert" -- penned almost all of INXS' music.

"There are five us in the band," Farriss says, "and we all have different opinions. But for me, I had a very art-related relationship with Michael Hutchence. We wrote songs together. It's a little different for me than for some of the other guys, because my relationship with Michael was like one of those classic relationships you have in bands, like Bono/Edge, Richards/Jagger, Lennon/McCartney.

"That relationship was severed when Michael died. I can't imagine, for some of those other bands, putting them in my shoes right now, how they would feel and cope. I can't imagine what they would do right now."

While it's conceivable that the eventual winner of "Rock Star: INXS" could be a new writing partner for Farriss, he's currently taking a broader view.

"I don't know the answer to that yet," he says. "I'd be lying if I said it can be done overnight or in the space of a day or two. The truth of it is that it develops over a long period of time. For the moment, because I'm a professional in what I do, I'm more interested in seeing what [the contestants'] interests are as people. Do they like poetry, painting? Do they have communications skills with people? How much do they read?"

Everyone knows about the wilder aspects of the rock 'n' roll lifestyle, but fans seldom to get to see the hard work that goes into creating the music and the performance. "Rock Star: INXS" has provided an opportunity to do just that.

"Rock 'n' roll is a business," says executive producer (with Mark Burnett and Lisa Hennessy) David Goffin. "Rock 'n' roll is a way of life. It's nice to think of it as a guitar-smashing party all the time, but the truth of the matter is, it's a serious family and business for INXS, in that order."