It’s remarkable to hear the voices and see the faces of black leaders who most of us have only read about.The filmmaker then goes to the black section of town, where the homes are cramped, streets rundown and the people dispirited. There, two young black men, one of whom has returned from duty in Vietnam, give a different view of the land of the free. Both men describe how lack of opportunity make it difficult to pull themselves out of the poverty they’ve lived with all their lives. These scenes are among hours of footage found with film of some the era’s great activists like Martin Luther King, Angela Davis and Huey Long in the basement of a Swedish television station. Producers Gören Hugo Olsson and Danny Glover organized their find into nine chapters, one for each year. The documentary includes interviews from the period and new commentary by artists Erykah Badu, Questlove, Talib Kweli and Harry Belafonte among others. It’s remarkable to hear the voices and see the faces of black leaders who most of us have only read about. I realized while watching the film that although I read Stokely Carmichael’s “Black Power” years ago, this was the first time I had ever seen him. The filmmakers show Carmichael during press conferences and speaking engagements, and interview him at home with his mother. It’s these rare, almost intimate moments, joking with reporters, talking to friends, even burning his draft card and singing, that make this larger than life figure, human, but at the same time, worthy of a degree of reverence. It’s hard not to feel grateful to the Swedes and our own Glover for this respectful and educational look at this period. Seeing the major events of the Civil Rights and Black Power movements juxtaposed with the forces that threatened them in “Black Power Mixtape 1967-1975” only heightens the sense that African Americans can accomplish great things when they pull together. Perhaps it takes an outsider and the passage of time to show you what’s possible. The movie opens Oct. 21 for a one-week run at the Violet Crown Theater.