Diehard metal fans have largely dismissed Meshuggah  as low-brow throwbacks until the band began amassing critical acclaim from unlikely sources: their 2004 EP I, a 21-minute track that had music geeks dusting off terms like "polyrhythms" and "hemiola" and received praise from The Wire among other non-metal pubs. The band's main fanbase, however, remains composed of longhaired dudes who prefer their music downtuned and growly. The Swedish quintet's latest, obZen, is catchier and thrashier than previous efforts, but still drops jaws with its complexity and brutality. Filled out by Cynic and the Faceless, tonight's bill promises prog rock for a generation raised under impending doom.