Tonight is Jingle Ball, the Z100 holiday concert that has, over the years, turned into a coronation ceremony for the new superstars of teen America. The brothers grew up in New Jersey, and just a few months ago they were still the kind of guys who would tenaciously call the radio station, trying to win tickets to the Ball. Now they're headlining. By the middle of 2008, the Jonas Brothers just might be the biggest teen band in the country. What's making them massive is not just their skill with sugar-dusted, girl-crazy gobs of pop. No, the Jonas Brothers are bound for bigness because, like Britney Spears and the New Kids on the Block and David Cassidy before them, they have been handpicked to summon all the desire, frustration, and spending power of the great American teen.

Within a few hours the dressing room starts to feel like a bunker. By nightfall, the narrow passageway leading to the room is clogged with chattering, unsupervised clusters of teenage girls in braces and low-slung jeans and UGG boots. Big Rob, the brothers' 395-pound bodyguard, glowers and shoos the girls away, but within minutes they're back, craning their necks, arching their backs, oh my God—ing into their cell phones, glossing their lips, batting their eyelashes, and fidgeting with their all-access passes. Now and then the door opens for a fleeting moment—when the film heavyweight Harvey Weinstein comes by with his daughter and a phalanx of her friends, and when Timbaland, decked out in a fur coat and a crucifix, pays an imperial visit. Each time the door slides open a couple of centimeters, the girls out in the hallway totally lose it and burst into gusts of shrieking.

While Nick concedes that "screaming girls are awesome," he insists that "we always kind of stand for being a role model and trying to make a difference, and I think this"—meaning the decision to wear the purity rings—"is just one of our ways of kind of like being different than everybody else out there." Think about that: Three guys in their hormonal prime—three healthy, handsome gents whose very job is to be besieged by swooning, text-messaging maidens who are finally old enough to attend concerts on their own—have committed themselves, publicly, to a policy of monastic celibacy. At the very same time, movies like Superbad and The 40-Year-Old Virgin are imprinting on a new generation the joyously raunchy mythology of losin' it. If the Osmonds were corn, this manifesto of squeaky-cleanness runs so flagrantly counter to the rock-and-roll ethos that it makes the Jonas Brothers seem like a strain of genetically modified super-corn.

In spite of its faint spritzing of punk, la musique des Jonas is still, of course, bubblegum. For decades now, bubblegum has been the lingua franca of American puberty, and it is the Jonas Brothers' good fortune to specialize in A-grade confectionary at the very moment when global corporations have figured out how to better transform these acts into massive, multi-tentacled beasts of American business.

There has always been a machine behind bubblegum, but what's different now is Disney. The company can, at this point in pop history, catapult an act like the Jonas Brothers to the kind of multimedia ubiquity that's rarely experienced outside the cult of Kim Jong-il in North Korea. "The business side of it has definitely changed," says David Smay, coeditor of the 2001 candy-pop bible Bubblegum Music Is the Naked Truth. "When you have a radio station and a TV station that are aimed at your market, the way Disney does, you can generate a hit band every other year. You can generate the content as well as own the distribution, and you can just pound on that market all day long."

The Jonas Brothers make their CDs for Disney's Hollywood Records. Their singles enjoy perpetual rotation on Radio Disney. Turn on the Disney Channel—the TV home of Hannah Montana and High School Musical—and you'll see the trio's videos and their guest appearance with Montana's Miley Cyrus. Their sugar-rush commercials for Baby Bottle Pop can be seen on ABC Family (Disney owns ABC) and Toon Disney. Toward the end of 2007, the Jonas Brothers built an audience as the opening act on the national Hannah Montana tour; on New Year's Eve they performed with Cyrus as part of Dick Clark's annual Times Square countdown, which was broadcast on ABC.

The Jonas Brothers even have a TV movie in the can—Camp Rock, which will air on the Disney Channel in June, just before their new album comes out on July 8—and whenever the Hollywood writers' strike ends, they'll get back to work on J.O.N.A.S., a Monkees-like TV series with a bubblegum-as-espionage premise. "It's an acronym for Junior Operatives Networking As Spies," Joe says. "We are secret agents, and our cover is that we're a band."

There's some serendipitous truth to that premise. The Jonas Brothers are the sons of Kevin Jonas Sr., a former Assemblies of God pastor and contemporary-Christian musician who now serves as one of their managers; and the Jonas family's original vision was to support Nick, a tousle-haired musical prodigy and a veteran of several Broadway shows, in his quest to break through as a Christian balladeer.

In January 2005 Steve Greenberg became the president of Columbia Records. Greenberg was known for having nurtured other young acts on the highway to hugeness—most notably, in 1997, a fresh-scrubbed fraternal trio called Hanson—and the first thing he did at Columbia was slog his way through a slush pile of demo tapes. "Only one thing really stuck out for me, which was this contemporary-Christian album by Nicholas Jonas," Greenberg says. "It wasn't a very good album. It was a very schmaltzy kind of record. But his voice was so good. I heard that voice and I thought, This is the best young person's voice that I've heard since Taylor Hanson. I've got to meet this guy." Greenberg discovered that Nick had two personable older brothers, and that the three of them had been mulling over the idea of forming an R&B-inflected trio. "They were trying to write songs where they would stand onstage and dance—to be like a boy band," Greenberg says. "And I said, 'This is all wrong! You guys should learn these instruments and you should be a rock band!'"

Greenberg says he burned the brothers a CD of punk songs from the seventies and eighties and rallied them into making a propulsive powder-punk album that would, as with Hanson's Middle of Nowhere, "appeal to young girls but also obtain the approval of critics." The 2006 album was called It's About Time, and its first single, "Mandy," was just chipping through on MTV's TRL when Greenberg was ousted in a management shake-up at Columbia. It's About Time was yanked and deleted from the roster, and the teen brothers were shown the door.

Disney's Hollywood label immediately signed the boys, while others were also hopping the trio's bullet train toward bubblegum destiny. The passageway at Madison Square Garden is filled with them: There's Big Rob, the bodyguard. And Felicia Culotta, the cheerful personal assistant with a Mississippi accent. And Johnny Wright, who managed the New Kids on the Block, and the Backstreet Boys, and, yep, Britney Spears. In fact, nine members of the team that handled Britney after her plaid-skirted 1999 breakthrough, including her bus driver, have offered up their services to the Jonas Brothers. You can't help but think of Team Britney as a pack of investment analysts who have knowingly shifted their allocations from one commodity trending downward to another on the rise. But it is that very name—Britney—that hovers like a cautionary, shorn-headed phantom above any band that wants to rule the fickle hordes of teen America. The Jonas Brothers, says their tour director, Rob Brenner, who worked with Spears for several years, "want to remain grounded. Those of us who have been around a lot have seen what happens if you don't."

Brenner insists that "you're not going to see these guys five years from now on Behind the Music saying 'Where did it all go?' I have permission from them to smack them around if they ever start acting like divas." And it must be pointed out that as they march through their Jingle Ball docket, making the rounds from sound check to meet and greet to press conference to performance, the brothers comport themselves with the kind of gentility and gratitude that we've come to expect from well-trained sound-bite-dispensing Mouseketeers. They take a walk through a frenzied Z100 gift lounge, where they're loaded up with loot while posing for pictures with everything from Bratz dolls to Foxers lingerie, and they pronounce the whole experience awesome.

They've played at the White House and met President Bush—that, too, was awesome. "With our manners, my mom always told us, 'I'm training you for when you sit at the president's table,'" Joe says. "It's really paid off. We try to be nice to everyone." Sure, there are times when some of the girls at the meet and greets can be a little forward, but the brothers have been taught how to handle that. "We've had some interesting situations with some fans, too—ones that will just come up and almost jump on you and be like, 'I love you, I love you!'" Joe says. "I guess the only thing we'd be willing to say is, like, 'Thank you.' It's kind of awkward when they're like, 'Oh, you're so hot!' How do you say anything to that?"

Disney is a machine, and the Mouse House seems to have met its perfect match in the Jonas Brothers. Then again, can a man stay squeaky-clean all the way into his twenties? And at what point does it begin to seem . . . odd? This line of reasoning helps explain why the purity rings are a sensitive topic. Already, Kevin says, bloggers and tabloids have taken to speculating about just how long those chastity vows will hold: "Oh, yeah, that's on a daily basis. People write that it's not true, that we're taking pictures with girls. Of course we take pictures with girls! They're our fans. I had a ring before this one, and I lost it in a wave pool on vacation"—at Atlantis, the deluxe, family-friendly resort in the Bahamas—"and I didn't have a ring on for, like, two, three weeks, and someone took a picture of me and then it was a huge rumor on the Internet." Achieving total awesomeness isn't easy, and when it comes to the preservation of purity, a band of silver makes a precariously slim line of defense.