Photo by Scott Irvine It’ll probably take a little more than a glass of warm milk to help you get to sleep after seeing this Bay Area-based band’s show. They perform with Stolen Babies at Solar Culture this Saturday at 8 p.m.

Pissing one’s pants at a museum is not a common occurrence. Then again, no museum has exhibited anything as menacing as Sleepytime Gorilla Museum, a Bay Area-based performance art band which might incite a little more than a loss of bladder control when they perform at Solar Culture on Saturday evening.

Watching the costumed multi-instrumentalists of SGM generate mouth-watering pandemonium with their adversarial lyrics and incomparable rock/semi-traditional rhythms is as frightful as it is awe-inspiring.

Lead vocalist Nils Frykdahl, violinist Carla Kihlstedt, percussionist Michael Mellender, bassist Dan Rathbun and drummer Matthias Bossi are acquiescent if not proud of their seemingly obscure fame and credit the success of creating their original sound to the fact that they’ve isolated themselves from mainstream music and the radio stations that play it.

“We are the most out-of-touch modern-day rock band you have ever met,” Bossi said. “You could play us any current mainstream music and we’d have no idea who it is except we’d all know that it sounds exactly the same.”

Call it an acquired sound, but an SGM album can sound like a harmonious combination of unidentifiable sound effects or easily mimic the score of an epic film, characteristics that make it tough to fathom such large sounds coming from only five musicians. But once you’ve examined the list of instruments SGM employs, you’ll understand why.

With the exception of instruments like the Autoharp, the xylophone-like Glockenspiel, something called a Viking Rowboat, the Toy Piano and the Swedish, violin-like Nyckelharpa, the most captivatingly unconventional instruments are the inventions of Rathbun.

“Dan has created any number of instruments and they’re all pretty much in use, give or take a tour or two,” Bossi said. “We’ve retired certain things for certain tours and then bring them to the limelight, or the forefront, for other things.”

These inventions include the notorious Electric Pancreas, the Slide-Piano Log, the Cockroach, the Pedal-action Wiggler, the One-stringed Warbler and Bossi’s favorite, the Vatican.

“The Vatican is just a confounded contraption with a bunch of shit hanging off of it,” he said. “I think it started its life as a cymbal stand and has now become a symbol of the Sleepytime Empire.”

With instruments like these, it’s no wonder SGM’s sound is unlike any other. Even more fascinating is the fact that they’re really good performance-wise. The operatic strength in Nils’ voice coupled with the piercing-as-ice vocals of Carla – who also does her thing on violin, Nyckelharpa and percussion guitar – is unreal against Mellender on guitar, brass, Electric Pancreas and that Vatican thingy.

Collectively, SGM’s influences stem from the appropriately avant-garde groups Swans, Art Bears and the ‘80s German anarchistic band Einstürzende Neubauten, members of which also used homemade instruments.

Any number of 20th-century classical composers are also on the list, according to Bossi, who has drawn personal inspiration from Stevie Wonder and the drumming of the 17-year-old Tony Williams “before he started playing bigger drums and playing really loud and bombastically when he was with Miles Davis in his early formative years,” he said.

The benefits of being an underground band far outweigh the burdens primarily because SGM maintains total creative control, Bossi said. From management and recording to touring and reaping in the profits, band mates have their say in all things SGM related.

“There is really no con to being a non-mainstream band,” Bossi said. “We have built the audience up one by one and we’re really proud of that. There are no strings attached. We don’t owe anyone anything. People just come out because they want to hear the music.”

And SGM’s fans are as diverse as their music.

“We do have a couple of converts; people who happened to just show up at a particular club because it’s the place that they drink,” Bossi said.

“We’re gonna run into those people where it’s like, ‘Yo man, I thought y’all were a bunch of fuckin’ faggots ‘til I heard your music, but I love you,’” he added, in an uncanny southern accent. “’I don’t like your dresses, I don’t like your makeup, I don’t like how you look, I don’t like how you smell. But your music sounds absolutely wonderful.’”

After releasing their first two albums, Grand Opening and Closing in 2001, and last November’s, Of Natural History, a standalone magnum opus, SGM have written a few tunes while on the road and plan to lay down the basics for a few in the studio once they’ve finished touring.

As for the Wildcat-generated myth that audience members actually piss themselves at SGM concerts, Bossi admits that his friend, Nick Doriss, came close to doing so when he saw his first SGM performance.

“We had a near miss…or, a near piss experience in Boston,” Bossi said. “(Doriss) used to think I was a jazzbo, and then he saw me play drums in this heavy rock band and said he’d almost pissed himself, which is great.”

The guys and gal of Sleepytime Gorilla Museum are looking forward to Tucson’s dry heat after playing a few shows in the south, particularly in South Carolina, in the 95-degree heat with 90-percent humidity.

“It was essentially the wettest, hottest show we’ve ever played,” Bossi said. “Except for Michael; the fucking bastard had the air conditioner shooting at his neck the whole night.”

Enduring the heat would probably be much easier for any other band considering the folks of SGM wear oil-based kabuki-like facial paint as well as elaborate costumes as part of their shtick.

A non-musical exhibit will include a “brute puppet show, which may or may not end up being a puppet show, but we’re still calling it a puppet show,” Bossi said. Other customary SGM exhibits will include “songs about ants, songs about bones and, of course, gospel music,” Bossi said. “We always bring out gospel music before a show.”

SGM also looks forward to playing with their good comrades of Stolen Babies. Bossi admits to loving the “brotherly rhythm section” of guitarist Gil Sharone and his drummer brother Rani, as well as the “absolute cuteitude” of lead singer Dominique Lenore Persi.

“They’re awesome. They’re just totally slammin,’” Bossi said. “She has a scream that could wake the dead. Really, unbelievable.”

Sleepytime Gorilla Museum perform with Stolen Babies at Solar Culture this Saturday at 8 p.m. Tickets are $7. For more information about SGM, visit sleepytimegorillamuseum.com.

Attendees with weak bladders are encouraged to bring a catheter.