Viking metal doesn't only come from actual Vikings' old pillaging grounds. Martriden, a band that hails from Montana, incorporates all the best elements of the horned-hat sub-genre: war-march drums, clarion guitar leads, majestic keyboard ambience and occasional folksy acoustics. The compositions on this year's full-length debut, The Unsettling Dark, mirror the terrain of the band's home state: They're expansive, with frequent mountainous peaks, and often gorgeous in a profoundly desolate way. Singer Michael Cook shrieks like a wraith, the rhythm section generates constant disconcerting rumbles and clicks, and guitarists Shane Howard and Will Thackery play riffs that either stride together in staggered lockstep or intertwine in tight spirals. Viking metal ranks among heavy music's most accessible offshoots, with a steady driving pace and anthemic choruses, and live performances only enhance its head-banging, fist-pumping qualities. With Corporal Mortification, Funeral Age, Alabaster Morgue, Immortal Divination. Studio Seven, 110 S. Horton St., 286-1312. 7:30 p.m., $7 adv, $9 dos. All ages.