Nigerian musician and revolutionary Fela Kuti was equal parts James Brown, John Coltrane, and Huey Newton. Outside of a few ex-record store employees and music geeks, almost nobody in America has heard of him. At least that was the case until a few years ago, when the unlikely Broadway hit “Fela!” made him a popular name to bandy about. That’s the one drawback to what could have been a compelling documentary: we have to watch Fela’s fascinating story through the filter of a bland musical. It’s kind of like if they made a movie about Bob Marley and the music was by UB40. Director Alex Gibney (“Taxi to the Dark Side”) should have done better; there’s too much frantic juxtaposition between the Broadway stage-show and actual killer footage of Fela and his band, Africa 70. Fela, who died of AIDs in 1997, deserves better treatment than this slice of milquetoast.