The thespian-turned-rocker is a well-worn cliché. Just pick a punchline: Keanu Reeves (Dogstar), Russell Crowe (30 Odd Foot of Grunts), Adrian Grenier (the Honey Brothers)...Jared Leto? Not so fast. While countless others may earnestly insist, ''Music is my real passion, man,'' the 35-year-old Leto, lead singer of the alternative band 30 Seconds to Mars, has become arguably the only successful recent actor to carve out a legitimate rock & roll career. ''There are plenty of examples of what not to do,'' Leto says, sinking into a grubby chair backstage at the Electric Factory rock club in Philadelphia. ''The landscape is littered with the bodies of dilettantes who have dared walk upon this holy ground,'' he adds sarcastically.
Indeed, Leto is not like the aforementioned wannabes: Music is not his hobby. The actor who came to fame as aloof heartthrob Jordan Catalano on the cult series My So-Called Life has taken on a new persona the makeup-wearing, stage-diving, fond-of-blood-spattered-costumes frontman with the same obsessive dedication he brings to his twisted film choices. The latest of these will debut at Sundance this month: Chapter 27, for which the sinewy Leto gained 65 pounds, transforming into John Lennon's fleshy assassin, Mark David Chapman. In the process, Leto contracted gout from the extreme weight change, thanks to a twice-daily regimen of microwaving and chugging two pints of Häagen-Dazs chocolate ice cream. ''My cholesterol was so high they wanted to put me on Lipitor,'' recalls Leto, now back to his normal weight. ''I took a wheelchair to set every morning because I couldn't walk more than a few feet without excruciating pain.''
For Leto, the music biz hasn't been much easier. He struggled to convince labels that the band he founded in the late '90s with his brother, drummer Shannon, 36, wasn't just a celeb bar band. Virgin eventually signed 30 Seconds, but their 2002 self-titled debut suffered disappointing sales and drew cynicism. ''Meet actor Jared Leto's so-called band,'' began Rolling Stone's scathing review. But Leto insists, ''I knew what I was walking into.'' He lowers his voice to a conspiratorial whisper: ''But. It. Did. Not. Deter. Me. For. One. Second.''
Fortunes changed after the foursome released a more radio-friendly second disc, A Beautiful Lie, in 2005. Slowly but steadily, it has sold nearly 600,000 copies roughly 596,000 more than the last CD from Kevin Bacon's band, the Bacon Brothers and spawned two alt-rock radio hits, ''The Kill'' and ''From Yesterday.'' 30 Seconds also headlined a 30-city, MTV2-sponsored tour. ''Like our music or not, people can't deny our legitimacy,'' Leto crows, kicking his Vans-clad feet up onto the coffee table. ''I could've made 20 movies in the past 10 years. I could be sitting in some big, stupid, ugly house in the Hollywood Hills without a care in the world. Achieving roomfuls of cash was never my goal.'' He motions a fingerless-gloved hand around the dingy room. ''I'm happy to be here.''
It's a scenario Leto could hardly have imagined as a kid. Born in Bossier City, La., he grew up ''food-stamp poor,'' listening to acts like Led Zeppelin and Pink Floyd, and, later, Nine Inch Nails and the Cure. His father left early on, so he and Shannon were raised by their nomadic hippie mother, who encouraged them to pick up paintbrushes and instruments. At 20 he moved to L.A., and soon after snagged the My So-Called Life role. When ABC pulled the plug, Leto gravitated to projects with artistic cachet, working on challenging, harrowing films such as American Psycho and Fight Club. ''I took the left-field work when I could have gone right.'' Leto even turned down Clint Eastwood's Flags of Our Fathers because the band had already committed to a 20-minute supporting slot on tour with emo act the Used. ''It certainly wasn't a decision I made with joy,'' he says now, ''but it was the right thing to do.'' Adds guitarist Tomo Milicevic: ''Sometimes I worry the guy is throwing his movie career away. We'll ask, 'Are you sure you want to do this?'''
Still, night after night, Leto spends hours mingling with the Goths and punks who flock to see him spin like a top and bellow with a throat-scarring roar. After playing to the Philly crowd, Leto signs autographs and doles out hugs until 3 a.m., when he steps on the bus for the nine-hour drive to Toronto. But sleep isn't on the agenda: He's editing 30 Seconds' video ''From Yesterday,'' a martial-arts epic he directed last summer in China.
As he cuts through the near-frenzied crowd, it's clear Leto is at ease. ''I am not a closeted musician wanting to act, or a closeted actor wanting to be a musician,'' he declares. ''I'm an actor and a musician. I don't need to apologize for either.''