On first listen, the Cave Singers might fool you into thinking they are a mellow folk band. Until, that is, you hear the raw, powerful, pinched vocals of lead singer Pete Quirk. They cut through the texture of fingerpicked acoustic guitar, brushed drums, and electric guitar chords on “Seeds of Night,” the opener to their 2007 debut Invitation Songs, drawing you into their sound world. The Cave Singers, who were once called “Seattle’s dirgiest dirge-folk trio,” are more than just a one-trick pony of sad, contemplative and elegiac songs. Their repertoire, now spanning three LPs, incorporates everything from the oddball love song “Helen,” to harder driving tunes like “At the Cut,” where guitarists Quirk and Derek Fudesco spin out bluesy riffs and distorted guitars over drummer Marty Lund’s rock exclamations. Still, they are incredibly powerful when they reach down for the darker places, exploring the depths of the metaphorical cave in which they sing with pulsating drums, repeated guitar licks, and sinister vocal stylings on “Dancing On Our Graves”: In concert, the Cave Singers bring an immediacy and intensity to their performance, somehow filling the stage with more sound than three folkies should be able to project. Yet, they still retain a certain elemental passion and drive. It sounds like music that would be equally at home on a deep forest camping trip, or on a sweaty dive bar stage. The latter venue seems like an appropriate location for a song like “Black Leaf,” a tune that traffics freely in scratchy punk guitars, edgy rock riffs, and grungy vocals. The Cave Singers came up through the Seattle scene alongside the Fleet Foxes, and with their new album, No Witch, released in early 2011, they’re poised for a breakout performance at ACL this year. Don’t miss it. Playing Friday, September 16.