As crazy as the lyrics are, the music itself is a model of discipline. Stoner metal is slower than other metal subgenres, and the steady, bludgeoning cadence of ‘‘Dopesmoker’’ really does sound like pilgrims trudging through an unforgiving landscape. (It took me about 20 listens before I appreciated how seamlessly the time signature shifts between 4/4, 6/8 and 3/4, a neat aural analogue to the complications of walking on loose sand.) Playing slow music at a deafening volume while keeping accurate time is mentally and physically draining. Sleep managed to keep it up for more than an hour. They basically recorded the song live, incorporating musical breaks every 16 minutes or so to accommodate the time limits of analog tapes. The physical constraints of the recording medium are probably the only thing that kept the arms of the drummer, Chris Hakius, from falling off.

‘‘Dopesmoker’’ is also really, really heavy: There’s a chord struck about 20 minutes in, after the song’s first guitar solo, that sounds like an avalanche having an orgasm. The guitarist Matt Pike tuned his instrument down two whole steps, to C, and the weight and sustain of that low C is mesmerizing; Pike returns to it again and again over the course of the song, a total of 1,818 times by my count. According to Billy Anderson, the recording engineer, the guitar tracks were recorded three separate times to thicken the sound, using custom-built amps so powerful that it wasn’t possible to stand in the same room with them. Each amp was recorded with seven or eight microphones, which gives you a sense of the dedication required to create something so loud.

The record’s sonic and spiritual heft is supplied in large part by the bassist and singer, Al Cisneros, who delivers the lyrics in a sort of roaring plainsong. The vast stretches of homorhythm — in which the guitar, bass and drums match individual syllables of the droning lyrics — create the sort of ominous ascetic feeling that I associate with chanting the Great Litany from my childhood in the Episcopal Church. Maybe this is where I should mention that the song’s original title was ‘‘Jerusalem’’ and that an early member of Sleep became a monk after quitting the band. If I’m really being honest, I should also admit that I experience the final few measures of ‘‘Dopesmoker’’ with the same exhausted, guilty relief I remember from the closing moments of a church service.

Was this music designed to be sacred someday? The essence of heavy metal is discipline in service of the preposterous. At its best, the genre solemnizes the impulses of adolescence. Couple this with the stoner’s habit of uncovering deep truths in whatever’s at hand and you might understand why Sleep’s magnum dopus can actually feel profound. For an atheist who misses the liturgical solemnity and theological strangeness of High Church, ‘‘Dopesmoker’’ delivers the next best thing. It reminds me of the heaviness of purpose required to chase the feather-light glee of the sacred.