Like many music documentaries, this profile of groundbreaking trumpet player and bandleader Miles Davis feels constrained by its conventional length, and devotes too little time to too many subjects. Director Stanley Nelson covers all the bases of Davis’s career, including his stint playing with Billy Eckstine’s big band as a teenager, his pioneering work in bebop, his 70s experiments with funk and rock, and his popular comeback in the 1980s. But since Nelson plays none of Davis’s compositions for more than 30 seconds or so, the viewer either has to know them already or take the word of the onscreen interviewees to recognize their brilliance. The film is more successful when it tackles Davis’s outsize and difficult personality; Nelson is up-front about the artist’s periods of drug addiction and his abusive treatment of his first wife, Frances Taylor. These revelations force us to wrestle with the fact that great artists can also be awful people.