Everyone knows something about the Rumble in the Jungle. Muhammad Ali beat George Foreman in the country formerly known as Zaire in 1974. A documentary about the fight, “When We Were Kings,’’ won an Oscar. Less well known is that the Rumble had a soundtrack.
Before the fight, James Brown, B.B. King, Bill Withers, Celia Cruz, The Spinners, Miriam Makeba, among others performed in a three-day concert, discussed at the time as the “black Woodstock.’’ It was a footnote in “When We Were Kings,’’ but one of that film’s editors, Jeffrey Levy-Hinte, has pared 125 hours of footage into “Soul Power,’’ a 93-minute freeform film of the festival. It rides in the “When We Were Kings’’ sidecar, a random abridgement that entertains despite its tendency to wander through a lot of terrific material.