Put 20 teenagers in a room with no adult telling them what to do, and the result could be chaos.

Not at the hip-hop dance studio run by Kelly Peters. The kids - all girls except for one - stroll in and start going over their moves. Before Mr. Peters even comes close to front and center, 17-year-old Lauren Beford of Oak Bluffs is leading the group through a series of stretches and strengthening exercises that give you a sense of just how rigorous hip-hop can be.

"Middle!" she calls out, and instantly, pairs of hands snap back to center. These young dancers, aged 10 to 18, are so limber they can touch forearms to the floor.

This is Kelly Peters's hand-picked crew, selected from his hip-hop dance classes that can number as many as 150 in the winter months.

Just two years ago, Mr. Peters had his doubts: Could a culture born on the streets of the Bronx translate into the lives of young Islanders, most of them white and middle-class?

The answer is an emphatic yes. In June, after bouncing between gyms, dojos and dance halls all over the Island, Mr. Peters opened his own studio in Vineyard Haven, freshly shingled and nestled behind mechanics' garages and a tire shop off State Road.

It's been a good year for Kelly Peters Dance. The last two summers, he and his crew traveled to Philadelphia for 10-day workshops dedicated to hip-hop. Just over a week ago, they performed at Six Flags New England in Agawam. And tomorrow morning, they hit national television, performing in front of cameras for CBS's The Early Show.

But even with all the success, Mr. Peters, his dancers and a number of parents watching from the sidelines insist there's more going on here than just nailing the right steps on the dance stage.

"Here, it's not just dancing," says one girl. "We didn't even know each other that well before this."

"We get together on weekends. We watch out for each other," says another. "In a lot of other dance classes, there's competition between people. Not here."

"It's like a family," says Chris White, the mother of 16-year-old dancer Ariel.

But camaraderie is just one payoff.

"You can get out more anger and emotions than with other dance," says one of the crew. "I do ballet and modern, but with hip-hop, the movements are stronger and more expressive."

"This outlet is the best thing. She's in perfect shape and has incredible self-esteem," says Gina James of her daughter, Jessica, 15. "I've never seen her so passionate about something. She wants a dance scholarship to college now."

"With the kids, what I want to get from them is confidence, the sense that they can do whatever they want," says Mr. Peters, the 32-year-old impresario.

But make no mistake, a big part of the confidence-building comes out of hard work, and Mr. Peters is both committed and demanding. This week, he ran the junior and senior crews through the paces in preparation for the CBS cameras in Manhattan.

"We have to get you guys toned up," he tells them.

Mr. Peters has an easy way about him. He has given all the kids nicknames, but he's more collegial than condescending. "Relax over there, Smitty," he says to one.

When Mr. Peters talks, no one is goofing off. "Jig-a-joo, jig-a-joo," he says, demonstrating the moves with shoulders and arms. "Set it up guys."

With a click of the remote control, the music's back on, a woman's voice floating above the loud, dominant bass. Out on the hardwood floor, the bodies respond in unison. Their first moves are industrial, mechanical, and then turn fluid.

"When I hear music, it takes over for me," says Mr. Peters, who grew up in St. Louis, transfixed and inspired by television and movie images ranging from Gene Kelly and West Side Story to Michael Jackson and Fred Berry, who played Rerun in the 1970's sitcom, What's Happening.

Mr. Peters, who has performed in music videos, on television and in New York city clubs, knows he has something unusual going on here on the Vineyard.

"When we performed at Faneuil Hall, there were these white ladies standing around watching. ‘Where'd you say you were from, Martha's Vineyard? No, they don't move like that on Martha's Vineyard,'" Mr. Peters recalls.

"That's what freaks people out the most," he says. "You expect it from black kids, but you don't expect it from white kids to move this way."

Indeed, they look good, dressed in gray, baggy sweatpants, white T-shirts and their suede Puma sneakers - the Clydes made famous by Walt Frazier.

Mr. Peters likes to say he's teaching them authentic hip-hop. It's not just dancing but a lifestyle, a philosophy that encompasses graffiti, deejaying, emceeing, beat boxing and fashion, just to name a few of the elements.

Parents are sensitive to the approach.

"He's dedicated to the old school of hip-hop, not this modern Britney Spears stuff. You see a lot of this Eminem, and a lot of people have this negative perception of hip-hop, but Kelly's finding the positive aspect of hip-hop, where there isn't the foul language," says Ms. White.

There's a history and a culture separate from the commercialism, Mr. Peters says.

"They're learning something about race relations, to understand another culture that started in a place that was urban and very poor," says Mr. Peters.

But this experience doesn't come across as anything like a history lesson. It looks like fun. The girls tease the only male crew member, Sam Nevin, a ninth grader from Edgartown. "He loves it," says one girl. "All his guy friends are jealous."

Laughter and smiles are a big part of the scene here.

"They're very loving with each other," says Mr. Peters.

Kids and parents hold the teacher responsible.

"It's his personality that commands the whole thing," says Ms. White. "Kelly is a spiritual and peaceful man. He instills a strong value in these kids. He wants it to be fun."

A lot has changed. "I was hesitant to start teaching," says Mr. Peters. "I thought these white kids aren't going to do this. Then I realized, and I know this, that my classes are more than about dance. They feel good about themselves here."