NEW YORK -- Just before 1 a.m. on Friday morning, Arnel Pineda walked to the front of a lounge-y space atop a hotel in this city's Meatpacking District. For the last few hours, the deejay had been spinning a typical mix of club hits, to the general indifference of the crowd. But that was about to change. Pineda, a diminutive man of 44 with jet-black hair and girlishly delicate features, took the mic. His eyes scrunched in concentration, he signaled quietly to the deejay, who cranked up a backing track. Pineda paused a moment, then began belting out the lyrics of Journey's rock anthem "Don't Stop Believin.' " Just a small town girl ...  Jolted by his voice, the crowd stopped its chit-chat. The drinks clinking died down. Then the cheering began. Living in a lonely world ...  The crowd went into a frenzy. Scores of cellphone cameras shot into the air. A woman of about 60 clambered atop a couch to get a better view, her husband looking less worried than he should have been. Then he hoisted himself up next to her. The impromptu musical performance came at a screening after-party for the Tribeca Film Festival premiere of the documentary "Don't Stop Believin': Everyman's Journey." Ramona Diaz's film tells the story of the titular band -- the one of arena-rock radio, "Glee" covers and "Sopranos" finales, but not, it should be said, the band of Steve Perry from the early 1980s (and, briefly, the late 1990s). Diaz's movie instead tells of the current Journey, with its out-of-left-field frontman. Even in the age of YouTube discoveries and "American Idol"-fueled fame, Pineda's tale stands out. A soft-spoken kid from a broken home in the Philippines, Pineda had been on his own since he was 13, even living for several years on the street. He eventually made a decent if not extravagant living as a musician, singing a mix of originals and covers, for a time in Hong Kong and then in Manila. But in 2007, his life took a dramatic turn. An ocean away, Journey guitarist Neal Schon was desperate for a new lead singer, his band having auditioned and rejected countless contenders. Messing around on YouTube late one night, Schon spotted Pineda singing "Faithfully" and other Journey hits. Stunned by how precisely Pineda mimicked the voice of Steve Perry (and, for that matter, Bon Jovi, Don Henley and other singers), Schon was enthused but wary. Could he have found his lead singer on YouTube? As Diaz chronicles (the director has Filipino roots but first learned of the band through a music-industry friend), Schon eventually flew to Manila to meet Pineda. Then Journey flew the singer back to their native San Francisco for a longer trial. Jonathan Cain, the multiinstumentalist and longtime Journey member, was skeptical. But Pineda won the musician over with his soaring range. The movie then follows Pineda as he embarks on a global tour with the band and attempts to adjust to life on the road. Singing for a few people in a studio or a Manila bar is one thing; keeping your composure in front of 20,000 screaming fans who expect you to sound like someone else--nicknamed "The Voice," no less--is another. At the Tribeca after-party, Cain expressed surprise at how the last five years have gone. "I was a doubter, I'll admit it, but he made me a believer," he told 24 Frames, shaking his head and looking on as a gaggle of 20-something girls surrounded a pleased if slightly overwhelmed Pineda, asking to take photos with him. "I've seen a lot in all my years of making music," Cain laughed. Didn't think I'd ever see this. (Don't ask him, incidentally, about the former lead singer who left in a ball of resentment: "Perry? He sticks his head in the sand. I mean, he'll listen to the stuff from his days but he doesn't like the stuff now. Cain added. I don't really get it. Arnel is keeping the legacy of the band alive. He's a big reason why a lot of people today know Journey.) In what may surprise many of the thirty- and fortysomethings who grew up listening to the band's arena-rock hits with a mixture of affection and eye-rolling, Journey remains a popular act. The band still tours extensively and is in fact set to go on the road this summer with Loverboy and Pat Benatar, a kind of rock-tinged '80s nostalgia reunion. The as-yet-undistributed Journey movie, members hope, will continue keeping their profile high, and feeds the flame for a new generation that barely knows of their '80s heyday. Hold on to that fee-eelin' ...  Pineda finished his rendition with the song's trademark rock-scream flourish, and the deejay went back to spinning his regular tracks. The singer handed off the mic, and dozens of people pushed to the front of the room to get a glimpse of the unlikely hero. Photos. More autographs. Pineda smiled. Then, looking happy but more than a little tired, he slipped out a side door. Tribeca 2012: Jason Segel's 'Five-Year Engagement' seeks ring Levon Helm, drummer and singer with rock's the Band, dies at 71 Photo: Neal Schon, left, Jonathan Cain and frontman Arnel Pineda of Journey at the Tribeca Film Festival.