Before the show started, the first thing you noticed was the small, round cactus that sat on a stool upstage like a cold, prickly Chekhovian gun. You could not wait for the thing to go off.

But before we can get to that, there were Lexie Mountain Boys. Lexie Mountain Boys are in fact four women from Baltimore who took the stage wearing CocoRosie makeup, blacked-out teeth, and intentionally white-trashy getups that look like they were nicked from Edith Massey's thrift shop. Their set consisted of them huddled around (and then rhythmically slapping or stomping on) a low wooden box while gibbering, giggling, hyperventilating, and occasionally singing. In one song, you could make out (maybe) the words "hamburger," "we got a hunger," and then some dry-heaving horking sounds. On another song, as one member was doing a kind of pained grunting, her bandmate said, "You really don't have to sing that if you don't want to." Between songs they engaged in hammy, winking banter, asking what the audience was eating and if people were on dates or maybe weren't quite sure ("Hey, it's the '90s!"). Again and again, the inside jokes and nonsense chants fell into easy rhythms, and it was hard to tell what was rehearsed and what was improvised, or how seriously any of it ought to be taken.

Anyway, the cactus. Matmos and So Percussion's set began with the four members of So Percussion coming out one by one to gather around the plant (which was connected to a contact microphone) and pluck its needles, creating intricate, plinking rhythms and microtonal melodies. The potential Blue Mannishness of this was quickly averted by Drew Daniel and M. C. Schmidt of Matmos joining in on bass-drum thump and ominous keyboard chords. For the second number, each member of So Percussion played a single woodblock, summoning swirling gamelan rhythms while Matmos looked on, grinning and bobbing their heads like two adorable jazz dorks. "Did the Lakers win?" Schmidt asked. "Jason wants to know. Is that good or bad?" Then: "It's sports—it's totally meaningless." (Cheers.) "I know my audience."

There were steel drums, melodicas, twinned flutes, singing saw, some sort of hand-cranked birdcall maker, a stylophone, a xylophone, a triangle, timpani, and bells. There were chains rattled, water scooped up from a bucket and poured back in (somehow not causing the entire theater to get up and go to the bathrooms), sheet metal wobbled, and cans of beer chugged, crushed, and scraped against mic'd surfaces. (Removing the cactus from its stool to replace it with that bucket of water, Schmidt fumbled briefly with a taped-down microphone cord, and Daniel teased, "Having stool trouble?") One song was an extended comedic monologue read by Schmidt through both a vocoder and a regular mic about beer, baseball, and a recovery sponsor named Joe.

The songs ranged from percussive workouts to loungey exotica tweaked into uncomfortable forms to glitchy, industrial throb to a triumphalist, polyrhythmic crescendo. You never know what to expect from Matmos, only that it will be exceptional. recommended