Do talent shows such as You're a Star, which starts on RTÉ this Sunday, offer a fast track to fame? Or is a stage school a more reliable route? Nadine O'Regan talks to young people involved in both.

Against the historic backdrop of Kilkenny castle, teenagers are readying themselves for a peculiarly modern form of battle. In the sprawl of the verdant grounds, they cluster in small groups or range alone over the grass, belting out chorus lines from pop songs.

The girls are spectacularly attired in a selection of fur coats, mini-skirts, denim catsuits, dresses, long boots, high heels and belly tops. The boys mostly sport black T-shirts, black trousers and silver necklaces, or plain white shirts open at the neck with jeans. Many are smiling and laughing, but not everyone is happy. One girl, standing outside the castle's Parade Tower Conference Centre, is grabbing hold of her mother's arm in panic. Another, sitting on the stone steps, clutching her guitar, has tension etched on her face.

A passing German tourist, bemused by the scene, smiles in comprehension when a one-word explanation is proffered. Everyone knows what the term Popstars signifies now. The television programme that deals in the hopes and dreams of wannabe superstars has gone global.

On this occasion, though, the format has some fresh twists. In the new show, entitled You're A Star, both solo artists and vocal groups will be eligible to compete for the grand prize, which includes a recording contract and, rather more dubiously, the chance to represent Ireland in the Eurovision Song Contest.

In addition, although judges Kerry McFadden (nee Katona), Phil Coulter and Popstars producer Darren Smith will decide who makes it through the first series of auditions, votes cast by the viewing public will ultimately determine the winner.

The programme will run for 20 weeks and profile each of the finalists in depth. Viewers will have the chance to admire the performers' excellence, laugh at their embarrassments and, perhaps all too often, bear witness to their distress. Nothing is behind the scenes anymore. And everyone who signs the consent form is fair game for the cameras.

Larry Bass, executive producer of You're A Star, bristles at this final comment. As the executive producer of the Irish version of Popstars last year, he received severe criticism from members of the public who were outraged by his programme's relentless coverage of weeping and wailing contestants. Bass believes the condemnation was undeserved.

"Not one soul complained to us about the way they were portrayed on TV," he says. "In fact, some people felt that they didn't see enough of themselves. Entertainment is tough. If people are really keen on a career in show business, then they've got something out of the auditions. The knocks are hard, but it's part of a learning process."

But perhaps there are easier ways of learning. In Fairview, Dublin, on the same weekend, the Billie Barry kids are spending the afternoon in rehearsals for their upcoming show at the Gaiety Theatre. As they practise their routines, clad in a motley assortment of leotards, pink satin ballgowns and tracksuits, there is a surprising amount of focus, confidence and professionalism in evidence. In addition, the kids are clearly enjoying themselves. There are no traces of tension or self-consciousness on display here. No tears.

In the past year, enrolments at the Billie Barry Stage School have risen by 25 per cent, in part, because of the screening of programmes like Popstars. Parents often ring the school's director, Lorraine Barry, in the hope that she can make their child into the next Samantha Mumba or Brian McFadden - both of whom are past pupils. But Barry is always quick to dispel such fanciful notions.

"We're not building people up into thinking that they're superstars," she says. "You need to have your two feet planted firmly on the ground. You can't afford to get carried away. There are so many talented people out there, and it always has to be the right person for the job."

Speaking to a dozen of the Billie Barry teenagers, it becomes clear that this philosophy has been well-absorbed. Contrary to popular perceptions, the students are pleasant and down-to-earth. Their approach towards show business is realistic; they know that they will have to be both gifted and lucky to succeed in their chosen fields.

Although some of their former classmates have auditioned for Popstars-style programmes, none of the group expresses any desire to follow their lead. In fact, many think that the contestants are making a big mistake.

"They just have this overall picture of fame and fortune, and they can't see past that," says 19-year-old Keith Hanna. "They don't think of what the consequences could be; they don't see that you could ruin yourself. They just jump in at the deep end and go for it."

Back in Kilkenny, 17-year-old Gillian Murphy talks about her reasons for attending the audition. "There's nothing like the Billie Barry school in Kilkenny," she says. "I would consider going there if I lived nearer, but I don't have that chance. With You're A Star, I have nothing to lose and everything to gain. If it's around, I'll go for it, you know?"

Many of her fellow contestants feel the same. Several of them even take the auditions over and over again, in different parts of the country. Sometimes this is because they hope to win through eventually. But just as often, it's because they want to learn from their experiences, and pick up useful advice from the judging panel.

Unlike the Billie Barry kids, many of these contestants have no one else to tell them honestly what their flaws are. Their dreams remain dreams, because they do not know how to improve themselves enough to turn them into reality. In this respect, finding out what their strengths and weakness are, even through the sometimes-cruel medium of television, could prove the making of them. Of course, it seems equally likely that it could be their undoing. Watching the auditions lends credence to both theories.

As the three judges laugh and chat among themselves, the contestants walk in nervously, many looking like they've just thrown up their lunch. Some succeed in presenting themselves well, but for others the strain proves too much. They begin hyperventilating and lose control of their voices. As the judges dismiss contestants, they are funny and informative, but often cruel too.

You're A Star judge Kerry McFadden defends their approach. "It's a hard job," she says. "It's a tough life. You're either made for it or you're not." Has she seen much talent over the course of the auditions so far? "No, nothing," she says, with a dismissive shrug. "They've been good, but nothing amazing."

Later that day, inside the Kilkenny train station, many of the disappointed hopefuls are readying themselves for the two-hour journey back home to Dublin. As they peel off their glitzy outfits in the toilets and emerge in tracksuits and denims, they attempt in vain to stop the tears from forming in their eyes.

On the train, there is a bunch of cheerful, middle-aged women who are clearly coming back from a weekend break. In high holiday spirits, they begin to sing. In the next carriage, where most of the rejected contestants are sitting, there is only the sound of silence. None of them feels like singing right now. As they've just discovered, it's not easy making a career out of something you love.

You're A Star will begin on RTÉ this Sunday at 6.30 p.m. The Billie Barry Stage School presents All I Wanna Do is Dance in the Gaiety Theatre from Tuesday, October 29th, to November 2nd.