To hear them tell it, the members of Tuatara could crank this kind of music out seven days a week.

"There's just an unlimited font of ideas coming out," drummer Barrett Martin said. The bearded percussionist was kicking back in a well-appointed conference room in the San Francisco hotel that he's currently sharing with fellow bandmembers Peter Buck -- better known as the guitarist for R.E.M. -- and Young Fresh Fellows/Minus Five's Scott McCaughey, who, along with Martin of the Screaming Trees, is in town assisting on the new R.E.M. album.

The result of this well-spring of musical ideas is the second Tuatara album in just over a year, Trading With the Enemy (mid-May), a dizzying 12-track instrumental ride that incorporates movie soundtrack-sounding pieces, cop rock a la '70s TV action-drama "Starsky and Hutch," a Japanese folk song and the odd township-jive groove thrown in for good measure.

"We performed a lot of this material on the road during the 'Magnificent Seven' tour," Martin said, referring to the three-pronged tour last fall that featured sets by Tuatara, crooner Mark Eitzel and McCaughey's skewed pop-band Minus Five. Eager to get those ideas laid down in a studio quickly, Buck and Martin -- along with new member McCaughey and charter members Justin Harwood (Luna) on bass and Skerik (Critters Buggin') on saxophones -- gathered last summer in a Seattle studio and recorded enough material on and off over six months for several albums. Additional musicians who contributed include Steve Berlin (Los Lobos) on saxophone/percussion, percussionist Elizabeth Pupo-Walker, two additional horn players and multi-instrumentalist Mike Stone of the Seattle band Devilhead.

The results run the gamut from the polyrhythmic vibe of the album's opener, "Streets of New Delhi" -- which unfolds over five minutes as a slinky, circa-1965 soundtrack to an Anglo-Indian spy caper -- to the cop-rock, car-chase rhythms of "The Bender" and the subtle, new agey strains of the Japanese folk tune "The Koto Song." Like their 1997 debut, Breaking the Ethers, the new album is eclectic enough to disorient anybody expecting the jangly guitars that Buck has perfected to an art in R.E.M., the moody grunge that Martin has grinded out with the Screaming Trees or even the off-kilter pop that McCaughey has created with his multiple side projects.

"The thing with my band," Buck said, speaking of R.E.M., "is that we take two years between records. This is more immediate." Buck said he sees some of the beauty of the wide-ranging Tuatara as the freedom from "conventional" pop music structures, especially since the band works without a vocalist. "I think if you ask Skerik, he would say it's pretty much a jazz band," Buck said. "If you ask Barrett, he would say it's an ethnic-rock band and if you ask me, I think it's a pop band that doesn't have a singer and so many traditional structures."

The lack of those "traditional structures" opens the band to such experiments as the loungy "Smuggler's Cove," a jazzy slow burn that feels like a lost track to a film noir thriller, or even "Fela the Conqueror," a Calypso tune that meanders from a bouncy African drum jam to jumping township jive.

Also included on the album are the songs: "Night In the Emerald City," "Negotiation," "Wormwood," "L'Espionage De Pomme De Terre," "The Angel & The Ass," "PCH" and "Afterburner."

"I think one of the main reasons why it's such a productive band is because we're all friends and we all like each other and each other's music and here's an opportunity to bounce ideas off each other," Martin said. "Plus, we all work really fast."

While each member brings a certain presence to the band, Martin said each also brings portions of what they've been denying themselves in their other projects. "I just personally like music that has kind-of a darker quality to it," said Martin, who could have been talking about the spooky night music of "Negotiation" or the moody, Morphine-like saxophone rock of "Afterburner."

"The Screaming Trees is like a dark pop band, but with an ambient quality to it," Martin said. "But I think you can still express beauty and have a positive approach to it. It doesn't have to be gothic." [Tues., March 10, 1998, 8:30 p.m. PST]