Upsilon Acrux
w/the Locust, Ex Models, the Plot to Blow Up the Eiffel Tower
Sun Feb 20, Neumo's, 7 pm, $10.

Temporary insanity--it's a condition that some of the best music induces. While most bands maybe nudge you to think about purchasing that bullet belt to complement your mohawk or going mushroom harvesting, Upsilon Acrux's music triggers a synaptic meltdown that obliterates all rational thought and makes equilibrium a distant memory. And that's always an exhilarating experience. Too bad it happens so rarely.

Upsilon toil in the sub-underground of American indie rock. They operate below the radar of most Pitchfork-reading/Insound-shopping hipsters. They've released four albums without causing much of a ripple, even in the consciousnesses of people who boast about letting Devendra Banhart sleep on their floor.

No matter. This San Diego quintet wring complex changes at the desolate intersection where math-rock spazziness collides with prog-rock virtuosity. Their fourth album, Volucris Avis Dirae-Arum reaches new summits of mind-fuckery, with Nick Lejejs' Moogs blurting out a kaleidoscope of foreign utterances and drummers Derek Burns and Jesse Appelhans evoking Keith Moon and Billy Cobham. If you harbor strong feelings for Orthrelm, Ruins, Don Caballero, Hella, or Mahavishnu Orchestra, you'll lose your pocket calculator over Upsilon Acrux.

To be honest, Volucris Avis Dirae-Arum will mainly appeal to the geekiest of the geeks, aspiring instrumental virtuosi, and the lonely, aging dudes you see at record conventions seeking Henry Cow LPs. But if you catch only one avant-rock/speed-jazz combo this year, make it Upsilon Acrux. They'll probably be able help with your trig homework, too.

segal@thestranger.com