When Kellen Asebroek moved from his native San Diego County to Oregon, he wasn't looking to get into a folky, bluegrassy band. At the time of the relocation, in 2005, he had scant knowledge of acoustic roots music. What Asebroek, a teenager at the time, had was enough self-knowledge to recognize that music, any kind of music, was going to be essential to his well-being."The only thing I knew was, I wanted to be in the music industry," he said.Asebroek has made his way into the music realm. He is a member of Fruition, a fast-rising quintet that has graduated to the bigger theaters in their Portland hometown, and has started to break into the festival scene, with appearances at the Northwest String Summit and Colorado's YarmonyGrass. On the day I spoke with Asebroek, he said he was "mostly recovered" from the previous night's shenanigans, which included opening for the Infamous Stringdusters in front of a crowded house at the Emerson Cultural Center in Bozeman, Mont.As to whether Asebroek's place in the music business includes being part of a folky, bluegrassy band, Asebroek isn't quite clear. Yes, Fruition features mandolin and upright bass, and the members take turns playing banjo; when it's not his turn on banjo, Asebroek specializes in acoustic guitar. The band's sound is built around coordinated harmonies, and the repertoire is filled with songs such as "Mountain Annie" and "Devil on My Shoulder" that suggest rural America. By all appearances, Fruition seems to have a dress code that mandates bowler or cowboy hat, a shirt that would fit in at the Grand Ole Opry, ragged jeans and ragged hair.But Asebroek vows that, when the band was formed, in 2008, none of its members was well-versed in bluegrass or folk. The first song Asebroek can recall playing with Mimi Naja and Jay Cobb Anderson, his current mates in Fruition, is "Satisfy My Soul," a Bob Marley tune. Anderson, the lead guitarist, has a set-up that is not of the folk world: His acoustic guitar is outfitted with a pair of P90 pickups ("super rock 'n' roll," according to Asebroek) and he plays through a Fender Twin ("a classic rock-type amp"). And in 2010, the band finally found the last piece of the combo in drummer Tyler Thompson."'Cause who doesn't want to rock?" Asebroek said of adding a drummer to the group.Hybrid styleFruition assembled more or less around Mimi Naja, a tomboyish looking Georgia native. Naja was visiting a friend who lived in Asebroek's Portland neighborhood; the two met and began playing together on the streets and in small bars. Not long after, Anderson and bassist Keith Simon, both transplants from Lewiston, Idaho, saw Naja perform in a club; like Asebroek, they were impressed with what they heard. "They had to meet her," Asebroek said. "They fell in love with her voice and her playing."The next day, Asebroek and Naja were heading out to their regular spot on Portland's Hawthorne Boulevard when they ran into Anderson. "We decided to combine forces," Asebroek said. "And realized right away we could nail three-part harmonies."For reasons that aren't even clear to the musicians involved, the sound that came out was straight out of old-time folk and bluegrass. "None of us listened to bluegrass or much country or even folk," said Asebroek, whose first musical experience had been piano lessons at the age of 9. "But something about us playing together, this is what we played. Out songs have a straight-up type sound."The setting might have had something to do with it too. Most of the early playing was busking on Hawthorne Boulevard in a happening section of Southeast Portland. The easiest thing to do was haul out acoustic instruments and play without electricity; a drum set would have been unwieldy on the sidewalk.Fruition - which plays tonight at Agave in Avon - has thus encountered the same debate about their bona fides that any band playing a hybrid style will face. "We get these old-school bluegrass guys in the front row, their arms crossed: 'This ain't bluegrass,'" Asebroek noted. "But we usually win them over."Asebroek doesn't care to enter the debate. "We get labeled as bluegrass. We don't mind that," he said.To drum, or not to drumThe biggest dividing point in the bluegrass realm is to drum or not to drum. For Fruition, that was an easy one. A few years ago, the band did a tour with the Bellboys, a group that had some overlap in membership with Fruition. By the end of the tour, the overlap was even greater, as Tyler Thompson, the Bellboys' drummer, was regularly joining in for Fruition's set."Then on the street, he'd sit in. He naturally assimilated into the band," Asebroek said. "You ask most bluegrass fans about drums, and they won't have it. But we all secretly wanted drums; it was just a matter of finding the right drummer for our songs."Fruition has made three recordings, but the only one to feature Thompson is the EP, "It Won't Be Long." The band is set to begin production of its next recording, its first full-length album with drums. Asebroek expects the group to test its wings outside the folk/bluegrass realm."There'll be a bluegrass song. But also a funky song, a Southern ballad, an old waltz," he said. "And it'll all sound like Fruition. Some bands can do all different styles and come off sounding like a cover band. Not us. Somehow, no matter what we play, it all sounds like Fruition."Instead of being an old-school bluegrass band, Fruition is part of the current wave of groups building the next generation of American roots music. The instruments look bluegrassy, but they are as likely to be influenced by '70s soft rock or Miles Davis as they are Flatt & Scruggs. Or, even more likely, they don't make much of the distinctions between various styles; it is all one big well to draw from, and they can piece together the parts as they please.Since being pegged as part of a bluegrass-type band, Asebroek has begun an exploration of bluegrass and country. He loves what he has heard; he counts Bill Monroe and Hank Williams among his favorite musicians. But he identifies more with modern groups such as Railroad Earth (who Fruition opened for during a New Year's run at Portland's Crystal Ballroom) and Hot Buttered Rum, who mix folk, rock, bluegrass and whatever else they consider to be their roots."There's a folk or roots music resurgence we're happy to be a part of and helping develop," Asebroek said. "It's a hybrid of the old good stuff; it's getting away from pop and getting back to the roots. The stuff on the surface of the music world is pretty bad. But a lot of fans and musicians wanted to get back to playing real, honest music that comes from the heart. People notice when you sing from the heart, spill your guts."