The words “Swiss music” and “badass” haven’t appeared together a ton over the years. Krokus aside, the mountainous nation’s modern troubadours have always tended to show more art than heart. But Zurich’s Celtic Frost squared that circle with 1987’s Into the Pandemonium, a startling muesli of classical music influences and shredding, robotic Eurometal. Sadly, the lure of the power ballad proved too strong for the Frost, whose 1988 hair-metal gambit Cold Lake neatly shed them of their hesher constituency on both sides of the Atlantic. None of which explains how Frost leader Tom Gabriel Warrior managed to reconstitute the band to make the excellent Monotheist, an album that contains “Ground,” which restores Jesus’ dying lament, “Oh God, why have you forsaken me?” to its natural, completely badass glory, and not one but three tunes that begin with the title “Triptych.” Celtic Frost performs with 1349, Sahg, and Inverted Trifixion at 7 p.m. at Jaxx Nightclub, 6355 Rolling Road, West Springfield, VA. $38. (703) 569-5940. (Andrew Beaujon)