While Matt Pike rampages across the earth with the swift-moving predatory dinosaur that is High on Fire, his former Sleep bandmates, bassist Al Cisneros and drummer Chris Hakius, slowly nurture their own formidable beast, the graceful, majestically heavy OM. On their last full-length, Conference of the Birds, and the two splits that followed--an EP with Current 93 and a single with Six Organs of Admittance--they made a religious discipline of droning, singsongy doom riffs, reimagining the Geezer Butler/Bill Ward holy dyadic communion as a bone-shaking shamanic ritual. The forthcoming Pilgrimage, due October 2 on Southern Lord, consists of four long cyclical tracks (recorded by Steve Albini) that are pleasurably punishing to brains and bowels alike. --Monica Kendrick
Since forming in Finland in 1991, CIRCLE have become one of the most forceful bands on the planet, not to mention one of the hardest to pin down. Stylistic leaps are their forte: heavy metal, Krautrock, drone, and space rock are almost always in the mix, but if you slap on any two consecutive records from their fat discography, there's a good chance the music will take a U-turn between them. In the past two years Circle have released seven albums and EPs--Katapult (No Quarter) is the latest--that reference everything from Judas Priest to Satie. Metallic guitar licks and postminimalist piano riffs mesh and split in ever-changing combinations as singer Mika Ratto shifts between satanic howling and gothic crooning. What makes it all work is the group's consistent emphasis on rhythm and repetition and their willingness to hold back at key moments, allowing the music to simply hover and breathe. --Peter Margasak
Om headlines; Circle, Endless Boogie, and Ecstatic Sunshine open. Om also plays Saturday with different openers; see separate Treatment item for details. a 9 PM, Empty Bottle, 1035 N. Western, 773-276-3600 or 866-468-3401, $12.