In one of the more unforgettable scenes from “For the Love of the Music: The Club 47 Folk Revival,” a recent documentary about the historic Cambridge venue now known as Club Passim, Jack Landrón essentially hurls a fireball at the screen.

Landrón, known back in the 1960s as Jackie Washington, one of the more popular folk musicians around town (and perhaps the only one of color), details how he felt like an outsider in a scene that was charged with supporting equality and progress.