A sporadically hard-selling homage to a cult hero from an overchronicled era, Radio Unnameable considers the career of Bob Fass, whose late-night free-form radio program of the same name on WBAI has kept New York City’s insomniacs and graveyard-shift workers company for almost 50 years. Fass, who had trained as an actor with Sanford Meisner, assumed his midnight-to-5:30 a.m., Monday-through-Friday berth at the left-leaning, listener-supported station in 1963, hosting visits and live studio performances by Bob Dylan, Phil Ochs, and Joni Mitchell—and saving at least one despondent soul from committing suicide on air. “Bob was everywhere it made sense for an activist to be,” notes Ed Sanders, one of many talking, graying heads assembled to lionize the DJ. Fass’ devising of or participation in various ’60s displays of civic-minded youthquaking—the fly-in at JFK, the sweep-in of the Village’s cruddy streets, the Yip-in at Grand Central Station—occasions overstatements from interviewees such as “It was sort of the forerunner of Twitter.” Increasing tumult at the notoriously chaotic, politically splintered WBAI led to Fass’ dismissal in 1977; he returned as a volunteer in 1983—a status he still holds, his hours cut to the midnight-to-3-a.m. slot on Thursdays only. Now 79, the man with the snow-white ponytail in the radio booth hasn’t flagged; as one of Fass’ contemporaries says, “He can let someone go on and on and on.”