“We just gotta go straight ahead, there’s still gonna be a festival, man,” Stewart Levine tells a worried phone caller. No matter the confusions, the misunderstandings, the missed connections. The 1974 concert in Kinshasa, Zaire will go on. You know this much already, especially if you’ve seen When We Were Kings, Leon Gast’s magnificent documentary on the Rumble in the Jungle, wherein Muhammad Ali rope-a-doped George Foreman. Where the 1996 documentary focused on the fight — and on Ali’s brilliant performance in and out of the ring — this one follows how the music came together. Using so-called outtakes from the first film, it screens 2 August at Stranger Than Fiction, and followed by a Q&A with director Jeffrey Kusama-Hinte, the film shows how the arrangements were made, how the stage was built, and how artists rehearsed. (It also includes a bit of Ali, following footage from Gast’s film: “The only reason the camera’s on me, the only reason I’m in the shape I’m in,” he tells an interviewer, is because I’m the greatest fighter in the world.”) While interviews suggest that participants just beginning to imagine an African diaspora aren’t quite aware of the daily and long-term effects of Zaire’s president Mobutu Sese Seko, the faith in culture and art to form community is palpable. The concert footage features incredible performances from B.B. King, Bill Withers, Miriam Makeba, and Celia Cruz. But the film follows the structure of the show, climaxing with James Brown (“I’m just glad to be here,” he says early on, pretending to be humble). In his Godfather of Soul jumpsuit, he’s filmed from multiple angles, dancers backing him, band perfect, and every nerve on fire. “The best of James Brown is yet to come,” he announces near the end. And you know it’s true.