I have to give this movie an A+. It is an outstanding treatment of the history of Jamaica, the Caribbean cultural blossoming after World War II, possible equilibria in individual human affairs, and of course the protagonist Bob Marley himself, as well as much much more. Marley by the way does not come off as a sympathetic character. The scenes from Zimbabwe and Germany are remarkable. The director is Kevin Macdonald, who also created The Last King of Scotland.
There are trailers here. Here is one good review. If you are seeking to normalize my review, in general I am not fond of “musical documentaries” and I do not consider Marley the peak of Jamaican music (I prefer Lee Perry, Desmond Dekker, and King Tubby, for a start). Think of this as a movie flat out and go see it on a large screen.