Milford Graves Full Mantis plays at Northwest Film Forum August 15–16 and 22–23.

Whatever preconceived notions you’ve harbored about free-jazz drummers—if indeed you think about these rare birds at all, you philistines—they probably don’t match up with the reality of Milford Graves’s odd life. Born in 1941 in Queens, New York, Graves became one of avant-garde music’s most out-there percussionists—and not just for his phenomenally inventive and nimble playing style.

Directors Jake Meginsky and Neil Young (not the famous rocker) take an aptly unconventional approach to their subject, scrambling Graves’s chronology like the drummer discombobulates meter on his kit. This ain’t your father’s typical music documentary—meaning, Henry Rollins and Thurston Moore (or any other musician, for that matter) don’t weigh in.

Milford Graves Full Mantis’ opening sequence focuses on an imposing African mask and then slowly pans back to reveal an array of unusual instruments and artifacts in Graves’s uniquely artful NYC home, to a soundtrack of ceremonial music with bass, gongs, and low chanting. This establishing shot could serve as an alternate beginning to Alejandro Jodorowsky’s The Holy Mountain.

Thus immersed in their subject’s spiritual, Afrocentric milieu, the directors roam through Graves’s artistic and intellectual pursuits with avid attention to detail. Sure, we get a lot of footage of Graves tattooing drumskins with improvisational zeal, from the ’70s to the current decade, and in many situations, including a gymnasium full of autistic Japanese children. And watching Graves in full flight, unleashing organized maelstroms, is breathtaking. He proved that free jazz foreshadowed punk rock and speed metal with its defiant disregard for sonic decorum.

But as enthralling as these passages are, the real substance of Full Mantis consists of Graves’s philosophies. “Gotta have the spirits, man,” Graves says in his backyard, talking about his grandfather’s old tools, which he incorporated into a sculpture, to remind him of the importance of self-reliance. The musician goes on to discuss how his garden is different from his neighbors’, because it represents many cultures. “Plants are constantly picking up cosmic energy,” Graves asserts and then proceeds to eat a leaf from a still-rooted spinach plant. The film leads you to believe that this cosmic energy eventually funnels into Graves’s limbs while he’s on the drum stool.

Full Mantis also explores Graves’s practice of a Chinese martial art, and how that applies to his playing. But perhaps the most fascinating scenes center on Graves’s obsession with the human heartbeat, an interest spurred by a 1973 recording of said biological phenomenon by Dr. George Geckeler. Soon after, Graves bought an electrocardiogram machine and started recording his visitors’ heartbeats; he wanted to discover how people are vibrating inside, the idiosyncrasies of their chi. He heard music in those readouts—very strange and engrossing music.

As riveting as some parts of Full Mantis are, this documentary probably won’t appeal to anyone but the most headstrong avant-music aficionados. The overall lack of context and information may leave the uninitiated adrift. But what an adventure awaits those bold enough to enter the film’s esoteric realm. recommended