EARLY LAST SUMMER, Andrew Bird walked onstage at the Southern music festival Bonnaroo and discovered thousands waiting for his first note. Later in the season, he played Lollapalooza in Chicago; again, a throng appeared. "Something happened," he says today.

What happened is that, after six albums (and a stint playing fiddle for hot jazz revisionists Squirrel Nut Zippers), Bird, 33, has finally found his audience. The Chicago native's singular pop style-which incorporates looped percussion, ghostly whistling, shifting meters, and deadpan singing that sounds both bored and bemused-has catapulted him from bars to selling out mid-size venues (he plays the Riviera on April 20th). His seventh album, the unpredictable but accessible Armchair Apocrypha, due out in March, will be released on the widely heralded Mississippi label Fat Possum, home to eccentric rockers (and Oak Park natives) The Fiery Furnaces.

A self-described music snob even as a student at Lake Forest High School, Bird chose jazz and the exotic sounds of Indian and Gypsy music over rock. "(Pop music) never spoke to me," he says. "It made me kind of sick." After earning a degree in violin performance at Northwestern, he beelined to rock clubs, not concert halls, and honed a reputation as a fiddler, a whistler, and a singer of hushed, esoteric lyrics. Ultimately, he traded his violin for a guitar and started to bring in sounds from jazz and blues: this juxtaposition of styles and moods made him stand out from the local music scene. "I had to earn it here. It wasn't easy," he says.

The days of riding his bicycle around town and hanging up posters for weekend gigs are gone, replaced by a new regimen that involves a tour manager, a sound man, and a bus. Touring is not kind on his body, but Bird admits that touting a new album with a new sound to a new audience is its own reward. "I just have that need to work myself to the point of hurting myself," he says. "It's a form of scarification just to know you're alive."