THE DAY I TALK to Joe Plummer, he'd just returned to Portland the day before—from New Zealand, ending a tour with Modest Mouse, the band he's been drumming with since 2004. Plummer's about to gear up for a quick jaunt with another little band he drums for, the Shins, who are embarking on a string of small club dates, presumably in preparation for another album. But he and I aren't talking about either of those bands; we're talking about yet another band the prolific drummer's involved with, a supergroup of sorts featuring Nick Thorburn (of Islands and the Unicorns) and Ryan Kattner (AKA Honus Honus of Philly group Man Man).

The trio calls itself Mister Heavenly, after one of the songs on its debut album—or, the song got its name from the group—which just came out this week on Sub Pop, and they're kicking off a tour here in Plummer's hometown of Portland. The obvious question is how he makes the transitions between three very different groups. "It's not super-duper hard," Plummer says. "I mean, sometimes it's tiring—but as long as I can breathe and move my arms and legs, I think that I should be able to do it, you know? I don't have any excuse otherwise."

Mister Heavenly was hatched when friends Thorburn and Kattner toyed with the idea of writing songs together; meanwhile, Kattner and Plummer already knew each other well from Man Man's tours with Modest Mouse, so they brought him out to Brooklyn to drum on some demos. "Everyone sort of had time off at the same time," Plummer says. "We didn't really know what we were gonna do with it. [Afterward] we went home and listened to the demos, and we all started liking it."

Those demos formed the groundwork for what became Out of Love, Mister Heavenly's charming debut. There are excellent '50s pastiches (and one crummy reggae song for good measure), but rather than a series of retro exercises, Out of Love indicates the kind of freedom that accompanies three musicians when they're trying on something new. "We didn't sit down and make a concrete plan," Plummer says, but the record shows acute pop sensibilities at work, via excellent tunes like the piano shuffle of "Charlyne" and the tightly wound fury of "Bronx Sniper."

The supergroup got even super-er with the addition of a temporary fourth member. Actor Michael Cera, who showed off legitimate musical chops in Scott Pilgrim vs. the World, played bass for Mister Heavenly for their first tour last December, spurring frenzy before the band even had a chance to release a record. As the group rehearsed here, Cera sightings around Portland became the gossip du jour.

"Nick is friends with him," says Plummer of Cera. "Nick and Michael would just hang out and play music together. At some point Nick just said, what do you guys think about maybe Michael trying to do it? And we thought, okay, why not? He's great, he's a great musician, great to hang out with. So that's how it happened: Nick and Michael are just friends and it fell together."

For this tour, the group will likely remain a trio: "There is probably not going to be a fourth member. Not quite sure yet," admits Plummer, who's also not ready to jump the gun on determining whether or not Mister Heavenly will remain an ongoing concern beyond this tour. "It's just something that we stumbled upon," he says of the group. "And so far, so good."