'WHENEVER you are onstage, it is always a heightened moment," says Sleepytime Gorilla Museum's guitarist and vocalist, Nils Frykdahl. "The situation is always potentially theatrical."

The theater holds a special fascination for Frykdahl, whose own exploits with the Gorilla Museum border on the fantastic. With shows that feature elaborate lighting, one-of-a-kind fabricated instruments, gender bending and ghoulish makeup, the group's appearances are equal parts theater and performance art.

Wrapped in layers of mythology and artifice, the group is taking the concept of the concert-as-art to a level unseen since the heady days of GG Allin, but with less testicular piercing and more violin. "Even if you are up onstage in a T-shirt and jeans, pretending to be a regular guy, that's a theatrical statement," Frykdahl says.

Taking its name from the Sleepytime Gorilla Press, an outlet for the written works of the American Futurist John Kane, the group coalesced in the East Bay in 2000. "It took a while to build up the courage to saddle a performing ensemble with such an ungainly name," Frykdahl says. "The amalgam of words is so uncomfortable."

On first approach, the composition of the band might seem equally ungainly. Carla Kihlstedt is better known for her intricate and frankly pretty violin work with the chamber ensemble Tin Hat, while Frykdahl and bassist Dan Rathbun joined the band after the disintegration of the very performance-heavy troupe, Idiot Flesh. The delicacy that Tin Hat is known for is nowhere to be found in the Sleepytime Gorilla Museum.

Often allied in print with the Anti-Humanist school of thought, the Museum's lyrics are as frightening and nihilistic as its costuming suggests. Songs like "FC Freedom Club" and "Bring Back the Apocalypse" detail the darker side of capitalism and environmental degradation.

But for all their shoutouts to obscure intellectual movements and forgotten writers, the members of the Museum see themselves as imminently populist. "We have no conception about who we are," Frykdahl claims. "We are sort of invading territory and seeing how it goes. People just want to be entertained. If we provoke them in some way, great."

If anything, Sleepytime's greatest heroes are the turn-of-the-century carnies and barkers whose exploits are enshrined in the Circus Museum in Baraboo, Wis. "Those people were the ultimate road crew," Frykdahl says days after touring the museum on a rare afternoon off. "They had a hundred train cars. They would do a one night stand, tear it down, travel and then set it all up to do it all again. That made us feel not so bad about what we do."

Like U2 or Beck, the Museum has to arrive a day before its performance just to set up the stage. Each tour, according to Frykdahl, "has added more lighting effects and gear and probably one new instrument." Bassist and producer Dan Rathbun has made instruments out of logs, saw blades and discarded metal with names like pedal action wiggler, electric pancreas and sledge hammer dulcimer. Loading these ungainly beasts into the bus is, in Frydahl's estimation, "a lot of work, but it keeps us from using our drink tickets."

For this excursion onto the road, the Museum is presenting yet another display of the bizarre and beautiful. The last human being, as personified by Shinichi Momo Koga, a Butoh dancer and clown, is an integral part of the present incarnation of the Sleepytime Gorilla Museum.

For the uninitiated, Butoh is a modern form of Japanese dance that involves odd angularities, ticks and grotesque movements presented in heavy makeup. According to Koga's own program notes, he spends most Sleepytime concerts squeezing through a series of different facial expressions while the band provides backup and counterpoint for his facial gyrations. "For the people of Mobile, Alabama," Frykdahl claims, "it is downright confounding. But it is a lot of fun to bring him to them."

Sleepytime Gorilla Museum plays Jan. 12, 8pm, at the Catalyst, 1011 Pacific Ave., Santa Cruz; $10-$15. (www.catalyst.inhousetickets.com)

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