directed by Charlotte Zwerin, Warner Home Video, 90 mins.

The special character of this portrait of the bebop piano genius Thelonious Monk is clear from its opening seconds. As the rest of his jazz quartet performs a slow blues, Monk performs an odd, slow spin onstage before sitting down to play something disjointedly melodic. He is slack-jawed at the sound he makes, and so will you be, for the music in this documentary is truly haunting. The filmmakers lucked into a substantial amount of unseen black-and-white footage of Monk shot in the sixties, and they have arranged their documentary around these candid moments.

Monk is the most enigmatic of the revolutionaries who changed jazz in the forties and fifties; we see him muttering during a recording session, joking at the Village Vanguard, dozing on a plane, and playing the piano with off-kilter certainty in baggy suits, raincoats, dark glasses, phony spectacles, and a wide array of cool hats. “Do your caps influence your music?” a Danish reporter asks him. “I don’t know,” says Monk. “Maybe.”

Born in 1917, Monk grew up largely on New York’s East Side and early on became house piano player for Minton’s. He struggled with bouts of depression that his son describes in the film; he would pace in silence for days. For the last dozen years of his life Monk refused to play. That he stopped was both mysterious and tragic, as this valuable film shows.