Includes d/l code. 

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.

The languid, dub-tinged "At Giza" is the band's most compellingly spare song to date. The title digs into the great pyramids and the words delve into those lake-sitting swans, the sun/waning moon, and seraphic forms. It's another Om avatar for a flight toward freedom/liberation. Sonically, where Variations constantly rocked, there are minutes upon minutes here of between and post-chorus breakdown, creating a dynamic surge when the echoed vocals push the song's "aviator" toward the sun and the bass rings with Hakius's recharged rolls and fills.

Lyrically, "Flight of the Eagle" follows a similar path, but from the start the bass is heavier and Cisneros' vocal pattern more clipped and Sabbathian, less serene. It's evocative of the last album, which I really dug, but now that the near perfectly modulated mellow-drama of that first trek's gone and "a new day dawns," the music loses steam. If the duo had found a way to continue the corked, opiate energy of "At Giza", Conference of the Birds would be totally brilliant; instead, it's got one great song plus one that makes me forget a little that I'd reached nirvana a few moments earlier.