SLEEP: The soul patch helps with the rockin; you see.

THE TRAJECTORY OF heavy metal in the 1980s was characterized by an accelerated push toward extremes. Specifically, the bands of that decade clamored for greater speed, heightened dexterity, and increasingly misanthropic themes. This is, after all, the time period that saw the birth of grindcore's blast-beat rhythms, thrash metal's technical indulgences, and death metal's morbid imagery. By the time Bush Sr. took office, there wasn't really anywhere else to go: You couldn't topple Napalm Death's tempos, you couldn't aspire beyond Voivod's level of musicianship without treading into dubious genre dabbling, and you couldn't get any more blasphemous than Deicide. Metal had apparently blown its load.

For a handful of bands at the turn of the decade, speed and agility had lost their luster. Similarly, the prevalent emphasis on shock value teetered on the verge of camp. Where had the hooks gone? Where were the gargantuan, throbbing guitar chords? Was the album cover art for Cannibal Corpse's Eaten Back to Life really necessary?

Sleep became pioneers not in continuing metal's arms race toward self-destruction, but in mining the past for its meat and potatoes, for reminding the metal community of what could be accomplished with one lone note cranked through a vintage tube amp and the punctuation of a forceful stomp on the kick drum, and for eschewing the Satanism shtick for ambiguous spiritual motifs. Still, Sleep didn't completely shed their peers' penchant for extremes; their final album, Dopesmoker, is comprised of one song clocking in at over an hour. Sleep's protracted song forms, lethargic tempos, and meditative riffs were, to some degree, reactionary responses to that era's sign of the times.

But this was hardly some petty stylistic backlash. Sleep's low-end liturgies reverberated through the metal community, establishing a new precedent toward deliberately ponderous forms. And while Dopesmoker stands as the ultimate expression of that aesthetic, Holy Mountain captures the band at their most resonate moment, when their constructions were still glacial in scope and speed, but parceled out in palpable movements. The excitement surrounding Sleep's reunion is proof positive that their lugubrious throbs are still felt throughout the metal world.