Any stoner metal nerd can tell you that when Sleep—arguably the genre’s most important band—split up in the mid-’90s, guitarist Matt Pike went on to embrace his ear-shattering physicality with High on Fire, while the rhythm section re-emerged as OM. In this configuration, the group has expanded on the powerfully cyclical oneness that made them legends: Al Cisneros’ paralyzing bass/vocal mantras and the methodical polyrhythms of drummer Chris Hakius were left bare in OM’s stark minimalism, while faithful fanatics drowned in a tsunami of hypnotically low frequencies. Sleep has since reformed to glorious acclaim, but Cisneros never stops cathartically chanting OM’s dark missives to the burgeoning legions. These days Emil Amos of Grails has taken over drum duties, while avant-garde soundscapist Robert Lowe augments the Valhallian rumble, lifting Cisneros’ blackened séance to the stratosphere.

by Chris Sutton