It began, of course, with the songs, actual folk music. Well, with Belafonte’s interpolation, which in its varied guises wed acoustic singing with Black spiritual arrangements and the sounds of the islands. He took his best-selling music on the road, to white audiences who’d pay a lot of money to watch him perform from his million-selling album “Calypso,” the one with “Day-O.” A major part of his knowing people was knowing that they watched TV. And rather than simply translate his hot-ticket cabaret act for American living rooms, Belafonte imagined something stranger and more alluring. In 1959, he somehow got CBS to broadcast “Tonight With Belafonte,” an hourlong studio performance that starts with a live commercial for Revlon (the night’s sponsor) and melts from the gleaming blond actor Barbara Britton (the ad’s pitchperson) into the sight of Black men amid shadows and great big chains.

They’re pantomiming hard labor while Belafonte belts a viscous version of “Bald Headed Woman.” The whole hour is just this sort of chilling: percussive work songs, big-bottomed gospel, moaning blues, dramatically spare sets that imply segregation and incarceration, the weather system that called herself Odetta. Belafonte never makes a direct speech about injustice. He trusts the songs and stagecraft to speak for themselves. Folks — Black folks, especially — will get it. It’s their music.

“The bleaker my acting prospects looked,” Belafonte wrote, in “My Song,” his memoir from 2011, “the more I threw myself into political organizing.” That organizing took familiar forms — marches, protests, rallies. Money. He helped underwrite the civil rights movement, paying for freedom rides. He maintained a life insurance policy on the Rev. Dr. Martin Luther King Jr., with Coretta Scott King as the beneficiary, because Dr. King didn’t believe he could afford it. The building he bought at 300 West End Avenue in Manhattan and converted into a 21-room palace seemed to double as the movement’s New York headquarters. (“Martin began drafting his antiwar speech in my apartment.”) So, yes, Belafonte was near the psychic core and administrative center of the movement.

But those bleak Hollywood prospects — some incalculable combination of racism and too-raw talent — kept Belafonte uniquely earthbound, doing a kind of cultural organizing. It wasn’t the movies that have kept him in so many people’s lives these many decades, though he never stopped acting altogether, best of all in a handful of Robert Altman films, particularly “Kansas City,” from 1996, in which he does some persuasive intimidation as an icy 1930s gangster named Seldom Seen. His organizing happened on TV, where he was prominently featured throughout the 1960s, as himself, and where his political reach was arguably as penetrating as his soul mate’s, on variety shows he produced that introduced America to Gloria Lynne and Odetta and John Lewis.