If you caught Om's Variations on a Theme, you know what to expect from Al Cisneros and Chris Hakius on the structurally similar follow-up, Conference of the Birds. Much like last time, the trance-inducing ex-Sleep rhythm section allows huge, slightly fluctuating bass grooves, mantra-style vocals, and locked-down drum ecstatics to unfurl as lengthy, addictive, metal-inflected incantations.

Musically, things have also changed ever so, especially in the case of the soothing, minimal, 16-minute opener, "At Giza", on which a vintage psych drum sound lends it a Silver Apples feel. One glorious, unshifting constant is Cisneros' penchant for mystical, elevated lyrical loops. Words are seemingly used both for their sounds (check out how he pronounces "sentient") as well as their meaning. Besides playing bass and sing-chanting in Om, Cisneros works as a chess instructor for kids in the Bay Area. Somehow that knowledge makes the repetitions and accents of his lyrics feel even more strategic, each word aiding in a flight toward some out-of-body lift-off into the ether.