As Primus' frontman, Les Claypool spent more than a decade concocting contorted musical passages and bizarre imagery to please no one but himself. In 1999, however, as his band prepared to craft Antipop, its eighth album, the bassist/vocalist found himself catering to his eclectic audience by writing what he thought they wanted to hear.

"We kind of shot ourselves in the foot," he admitted over the phone from his San Francisco home. "That record was the least successful one we did. It was still a great record, but it wasn't something we made simply for ourselves."

Now separated, at least temporarily, from his Primus bandmates, Claypool is diving back into selfish, improvisational songcraft with Oysterhead, the old-fashioned supergroup he formed with Phish guitarist Trey Anastasio and Police drummer Stewart Copeland. The band's debut, The Grand Pecking Order, is a remarkably fresh-sounding disc combining each member's talents without sounding like a mishmash of their former bands.

"Our prime focus was to not bring anything preconceived to the table," Anastasio recalled. "I was excited to go into the studio and see what our blend of personalities would result in. We kind of wrote the songs on the fly, but we consciously wanted a soup instead of three appetizers."

Surreal and groovin', though less willfully weird than Primus or as jammy as Phish, Oysterhead cultivate vibrant, uncommercial music that fuses aspects of rock, funk jazz and psychedelia. "Little Faces," Pecking Order's lead track, opens with sonar beeps over a staggered marching beat, then morphs into waves of tumescent bass, funky wah-wah guitar squiggles and arguably nonsensical lyrics. Then it gets really strange. "Army's on Ecstasy" is an upbeat ditty with cartoony vocals (concerning a dosed military) and wiggy blues guitar. And the first single, "Mr. Oysterhead," sprawls and undulates to a galactic rhythm, sturdy beat and alluring array of guitar lines.

Oysterhead formed in May, when Claypool was invited by Superfly Productions in New Orleans to assemble a band for the production company's annual Jazz and Heritage Festival Superjam. He asked Anastasio, whom he knew from the jam scene, if he was interested in joining forces. After brainstorming about who would be their ideal drummer, Anastasio suggested Copeland.

"I threw his name out there half-jokingly," the guitarist recalled. "I really think he's the most important drummer in rock after John Bonham. I was a huge Police fan in high school. It turned out he had produced a track for Primus, so Les called him and he wanted to do it."

The trio convened in New Orleans, wrote seven songs in three days, then played a 3,000-seat theater in front of an audience that included director Francis Ford Coppola and "Simpsons" creator Matt Groening. The show was intended to be a once-in-a-lifetime convergence, but the vibe was so strong, Oysterhead decided to write a full album.

"We recorded the show," recalled Claypool, "and Stewart was all hot to release it. I thought it was good, but the performance was kind of rough. I knew it could be so much better because I knew we had this amazing chemistry."

Claypool's instincts didn't fail him. Although there were a few ego conflicts at first, since all three bandmembers were used to steering their own ships, the music soon fell together and the band started vibing magically off each other.

"I've never had a situation where I'm writing lyrics with somebody and we're completing each other's sentences," Claypool said. "It was amazing."

"It was all about throwing spaghetti at the wall and seeing what stuck. But it wasn't just a lot of jamming," Anastasio added. "It was team songwriting, very collaborative."

Oysterhead begin a national tour in support of The Grand Pecking Order on October 21 in Seattle. The trek ends in Gainesville, Florida, on November 18. After that, Claypool will return to the drawing room to work on new songs for another band, Les Claypool and the Fearless Flying Frog Brigade, Copeland will return to producing other bands and creating film soundtracks and Anastasio will work on a variety of different musical projects he's not yet willing to discuss.

"We may go out again as Oysterhead next spring or summer," Claypool said. "It depends on how much fun we have. One of the great things about this band is we all still have our day jobs, so we don't need to hammer it into the ground."