ONLY a few years ago, Jonathan Daniel had hit 40 as a failed hair-metal god replete with gray hair, stolid paunch and a penchant for faded, tapered denim jeans. Bob McLynn, a Mr. Clean look-alike one decade younger, was a failed post-hardcore bass player living off a deficit account.

So it makes an odd kind of poetic sense that together, as the masterminds behind the New York-based agency Crush Management, they are responsible for some of the most popular, ubiquitous and critically savaged emo/pop-punk bands of the moment – Fall Out Boy, Panic! At the Disco, The Academy Is . . . basically, any band that a 13-year-old girl with a blog and Hot Topic habit obsesses over.

“[I thought] as long as I could figure out how to make money with artists, it’ll be a business,” says Daniel, whose face shines with a fine film of sweat and who punctuates nearly every thought with a high-pitched, machine-gun-style laugh. “And the turning point came when I found Fall Out Boy.”

How Daniel found Fall Out Boy is in dispute (he says he stumbled across a song on the Web; FOB bassist/lyricist Pete Wentz recalls mailing in a tape), but the band was the first act Daniel and McLynn signed to their struggling company – though Daniel was skeptical.

“I was like, ‘I don’t know. They’re so green,’ ” he recalls. “But Bob was like, ‘I know what to do.’ ”

McLynn threw the band in a van and had them tour the country for a year, while Wentz intuitively built up a fan base – albeit primarily among 13-year-olds – by creating a patina of intimacy with them online. Which, to suburban girls suffering from strip-mall ennui, felt very real.

“And then I went to see FOB down at the Continental for a little Sunday afternoon show, and there were 300 kids there, at 3 in the afternoon, singing every word to every song,” says Daniel. “I started going crazy. This was the new way to reach kids.”

Fall Out Boy’s success has spawned a legion of sound-alike, look-alike bands, several of which are now signed to Crush, including Panic! and Academy – both discovered by Wentz. He also encouraged Crush to sign the supremely goofy rap-rock outfit Gym Class Heroes, who just had a No. 1 hit with “Cupid’s Chokehold.”

Much like Lou Pearlman – the crooked impresario who created and controlled the ubiquitous boy bands of the mid- to late ’90s – the guys behind Crush

have successfully marketed a critically dismissed, yet commercially successful, stable of cute boy bands to timid teenage girls not yet ready for real rebellion.

“It’s no different than *NSYNC with guitars,” says Butch Walker, a producer and songwriter who has worked with FOB and Academy. “Which they’re not. But I don’t think [these] kids are as critically discerning as they would be if they were older.”

Crush’s management style borrows from Pearlman’s business model, as well as parts of Motown and the Brill Building. They’re a factory, operating out of a single loft-like office space on East 11th Street.

The recording studio is in the back, as is the in-house producer, a lanky, talkative 37-year-old journeyman named Sam Hollander. The merchandising is run out of the front. The on-call video director, a super-chill 38-year-old “Sound of Music” obsessive named Alan Ferguson, has a room of his own, littered with candles and DVDs of old Hollywood musicals, while core songwriter and producer Walker is based out of Los Angeles.

Shrewdly, Crush simply manages this team. None of these artists is on the Crush payroll, but when they work with Crush artists, Daniel and McLynn – who pointedly and often refer to their company as a “family” – get a cut.

“It’s not as ugly, seedy, inside-job as it seems with us,” says Walker. “It’s really like a family.”

Until now, Daniel and McLynn have intentionally remained anonymous, which allows their biggest bands to seem like part of an organic movement rather than extensions of a calculated, cultivated brand.

Fall Out Boy, Panic! and Academy specialize in baroque videos with narratives not seen since the ’80s, as well as logorrheic song titles only an adolescent could love: “Get Busy Living or Get Busy Dying (Do Your Part To Save the Scene and Stop Going to Shows),” “Champagne for My Real Friends, Real Pain for My Sham Friends” – Fall Out Boy tracks both. “The kids get so deep on the lyrics,” says McLynn. “They speak to kids on a level that no one’s spoken to them before.”

Also unofficially employed by Crush is Fall Out Boy lyricist/bassist Wentz, the band’s most famous member and the elfin, guylinered mascot of the entire scene. A pop-culture obsessive who spends an inordinate amount of time online, Wentz basically works as their A&R guy, having signed all three bands to his own label, Decaydence, which is also managed by Crush, as is Wentz’s clothing line, Clandestine.

“It can get incestuous,” Wentz concedes. “Crush manages everything I do – almost everything. I pee on my own. But it’s a trickle-down theory of economics that really works.”

“Wentz is an entrepreneur,” says Walker. “He was a bored kid from the suburbs who was like, ‘I’m gonna have more T-shirts to sell than songs in my set list.’ ”

Wentz himself – who recently hit a new, Us Weekly level of celebrity by hooking up with the dubious likes of Ashlee Simpson – admits that “Fall Out Boy is the way I support my lifestyle.”

“All the bands judge each other by how much merch they sell,” says Daniel.

Such crass commercialism has long had its place in hip-hop – Wentz himself aspires to be like his mentor and Island/Def Jam president Jay-Z – but in Wentz’s scene, not so much. This makes him one of the most loathed figures in rock, suspected of exploiting his fans’ false sense of a confessional community in the interest of selling CDs at $20 a pop. And the Crush bands are among the very few, in the age of file-sharing and downloads, who can; FOB’s latest record, “Infinity on High,” debuted at No. 1 on the Billboard charts.

Yet these profit-margins haven’t translated to critical respect, or fans over the average age of 15. Daniel, to his credit, isn’t so shocked. He admits that the bulk of his bands aren’t so familiar with rock.

“Panic! in particular – I think their musical history traces back to the first Third Eye Blind album,” he says. “That’s it. Like, the guy producing their record gave them ‘The Beatles Anthology.’ And they were very excited, but they didn’t know any of it.”

Also, Daniel thinks that FOB and its spawn are disparaged by critics because “they’re very much like the hair bands of the ’80s, like Motley Crue – it’s, like, heavy metal for girls. This scene is very much like that. It’s very female-based.”

“He couldn’t be more on the mark,” says producer Hollander of Daniel’s assessment. “Dead on. If you were a hipster, like I was at that, age – God, you wanted to laugh at it. That’s exactly right.”

“It’s not edgy,” says songwriter Walker (he’s also written and produced for Pink, Avril Lavigne and Bowling for Soup). “It’s no different than the hair metal movement that Bon Jovi pioneered,” he says. “When those girls outgrew New Kids on the Block and Debbie Gibson and started smoking cigarettes and hanging out with boys who drive Camaros, they started listening to Bon Jovi. And that music was not good either.”

Walker, whose tastes run more toward the Arcade Fire, concedes that a lot of the Crush bands sound “so same-y – they all have the same look, play the same guitar songs, all the songs are about the same s – – -. I think that’s why the critics don’t like it.” He pauses. “Jonathan may not be the poster boy for what is indie-cred cool, but if he was, he wouldn’t be successful. Let’s not have our head up our ass and shoot ourselves in the head with the hipster gun. And I think that’s why the company is equally loved and loathed.”

To Wentz, it’s all just white noise. He sees himself as one in a long line of great artists who, in their prime, were profoundly misunderstood: “You know, Bob Dylan plugged in and everyone started booing,” he says. “Thirty years later, he’s hailed as one of the greatest artists of all time. There are plenty of ways to get rich. It’s very easy. But if you want to be involved in this, you want to be involved for the legacy of your art.”

He prefers to see himself and Crush as a latter-day version of Andy Warhol’s Factory. “The most important thing is the brand, and the shift in popular culture we’re making,” he says. “We don’t have meetings about what color we should dye our hair.”

And so next month, the band – which to date has employed monkeys, Wentz’s dog Hemingway, and Kim Kardashian in its videos – will expand its navel-gazing oeuvre by shooting its next video in Uganda.

“Pete and the band want to focus a lot of attention on humanitarian efforts,” says director Ferguson. “The band is going to meet at orphanages, political leaders. Fall Out Boy will play at a school, for example. You know those big, inflatable things that kids jump on at carnivals? We’re gonna bring one of those to the orphanages for a day so the kids can play with it.”

Trickier, he says, is capturing the mood: “I need to make it compelling. You don’t want it to look like a Sally Struthers commercial. This is a ‘TRL’ video.”

But for now, there’s a tour to wrap up: FOB played Jones Beach last night, along with Crush stablemates Academy and Cobra Starship, after which Wentz headed over to his 28th birthday party at Angels & Kings – a theme park-y dive bar in the East Village recently bought by Crush (all their artists are investors).

The opening night party hosted Jay-Z, Helena Christensen and Kate Bosworth, though of course the Crush guys prefer to position it as just a dirty little clubhouse for their artists. Wentz, hilariously, told The Post at the opening that his own bar was a necessity because he wasn’t “cool enough” to get into most clubs. “We just want someplace where we can hang out and be ourselves.” And which, no doubt, will lure kids from Long Island and New Jersey, hoping to “hang out” with their favorite uncool, superfamous rock stars.

Wentz and Crush, though, aren’t worried about the little girls catching on. “I feel like our fans could smell a fake,” Wentz says. “I do the things I believe in.”

“Wentz, as much as he is hated on by the cred kids – they have no idea what kind of force they’re reckoning with,” Walker adds. “A lot of people think he’s cashing in on empathy and pain. But whatever.”

maureen.callahan@nypost.com