Philadelphia’s large, slow-moving veteran psychedelic collective Bardo Pond has never been much for adapting. Over the past 20 years, the band has allowed its monstrous, distortion-dredged rock to trudge along at sub-evolution speeds, churning up reliably druggy albums full of folky melody and all the subtlety of a woolly mammoth. Its new self-titled album is a progression—but only barely. Slightly shaggier and more ragged than its predecessor, 2006’s Ticket Crystals, Bardo Pond sounds like the group is practically devouring its microphones as it records; the semi-acoustic opener, “Just Once,” drips with the honeyed, sultry vocals of frontwoman Isobel Sollenberger before shit goes up in the smoke of a dozen overdriven amps. (And maybe some weed.) The stoner gospel of “Don’t Know About You” is appropriately apocalyptic, and as its centerpiece, the disc offers “Undone,” a 20-minute ceremony of sonic shamanism that worships drones as the voices of gods and whammy pedals as holy artifacts. At this rate, Bardo Pond should have a fresh take on its primordial sound ready by the advent of the next millennium. Not that there’s any hurry.