Strange things happen when Douglas Koyama opens his mouth. Sounds spring forth and combine into rhythmic phrases, then stack into layered constructions. It might seem like magic, unless you know that he’s using a digital looper to create his improvised excursions, and even then it’s still quite beguiling, a gentle and melodic take on an avant-garde technique that has its roots in Steve Reich and Terry Riley’s experiments of the 1960s.

Koyama didn’t come to his style through the new-music underground, however. Instead, he started with a musical-theatre troupe in his hometown, Quesnel—and when the company brought in Vancouver-based singer and consultant David Hatfield to teach vocal technique, he had one of those “eureka” moments.

“David came up and did a four-day workshop with a bunch of us, and it kind of lit a fire inside me,” Koyama recalls, on the line from the Cariboo, before heading to this weekend’s musically diverse Powell Street Festival. “I wanted to sing with people, so the day after the workshop, I invited everyone to sing at my place and six people came. The next day, three people came. And then no one came. So I went and bought a loop pedal and started singing with myself, and it’s just evolved from there.”

Looping, he says, is a way of generating compositional structures in real time. “It allows, more than anything, an exploration of what music is. I’ve learned that if you take pretty much anything and put it into a circle, the fourth time you listen to it, it’s become a rhythm. And then I just feed off the harmonics, or add little accents. It’s hard to describe, but basically whatever sounds good next is what I use.”

Although Koyama considers himself “a person first, a Canadian second, and maybe a Japanese Canadian somewhere after that”, his participation in the Powell Street Festival this weekend signals that he can trace his ancestry to Japan—and that Vancouver’s annual celebration of Japanese and Japanese Canadian culture has open ears when it comes to music.

On the more traditional side, this year’s festival features Katari Taiko, Canada’s longest-running Japanese percussion ensemble—and one that just a couple of years ago was in need of reinvention.

“At the time, there were two senior members left in the performing group, and all the rest of the members of the group had only been playing, I think, about a year and a half,” says Tiffany Tamaribuchi, the California-based percussionist and Jodaiko bandleader who’s been mentoring the local troupe. “So basically my job was to come in and just sort of work with folks to give them a little bit of a starter foundation in taiko, and try and help get them ready to perform more.”

With that in mind, she’s penned a new composition for the ensemble, one that she says “challenges them to stretch into the concept of ma, which is the Japanese sense of timing or using negative space.

“I want to sort of push them a little bit towards a more creative physical expression on-stage,” she says, adding that Jodaiko and Katari Taiko will also perform at the Cultch next Saturday (August 10). It’s not by chance that this booking coincides with the Powell Street affair.

“Powell Street is one of the longest-running Japanese festivals in North America,” Tamaribuchi explains. “I’ve got friends from California, Seattle, and Oregon that come up, just because it is this sort of treasured experience, where you can taste traditional Japanese festival food, you can see some really amazing contemporary Japanese-Canadian and Japanese-American art, and experience the community coming together.”

That’s something Joseph Hirabayashi knows well. As the son of Kokoro Dance founders and frequent festival performers Jay Hirabayashi and Barbara Bourget, he’s been coming to the festival since he was a small child, and for the past several seasons he’s also accompanied the whitewashed butoh specialists on keyboard. Not this year, though.

“They’re not doing the festival, because they’re going to Japan,” he notes. “But, yeah, it’s always been, for me, a really, really great cultural awakening of my Japanese-Canadian heritage. I also like that there’s definitely a super-big amount of eclecticism presented at the festival, and that the bounds of what is considered traditional have definitely changed a lot. It’s not a conservative festival.”

This year, Hirabayashi will perform with his four-piece band Spring. Formerly the math-rock-inclined SSRIs, the unit has changed its name to reflect personnel shifts as well as a move toward a somewhat more relaxed form of psychedelic folk. And while the pianist doesn’t hear any overtly Japanese elements in his band’s sound, he does feel a link to what’s currently going on in the Tokyo underground.

“We’ve met all these bands that are from this more experimental Japanese indie-music scene, and it’s really interesting because it’s kind of our scene, too. It’s like ‘Whoa, weird! How are these bands so like-minded?’ ” he says. “I think we’re very technical, and that’s something I’ve noticed about the bands that I’ve seen out of Japan. They’re more technical, I think, than a lot of bands that are in Vancouver, and we’re also definitely very craft-oriented.

“But to say that’s because I’m a quarter Japanese? I think that it’s more about the people in the band. We’ve all gone to jazz school; we’re trained musicians. But we’re not afraid to get noisy!”

Neither is the Powell Street Festival. Part family-friendly picnic in the park and part exploratory arts showcase, it’s utterly unique.