I love, love, love music documentaries. The great ones have a great story to tell. I also believe that the ones about bands have some lessons for people starting businesses and dealing with cofounder friction, creative dynamics, licensing, etc. Many of them also deal with the impact of technology on recording, performing, and marketing. Recommended:
"Soundbreaking: Stories from the cutting edge of recorded music" (PBS documentary on history of sound recording) (http://www.pbs.org/soundbreaking/home/)
People love to hate on "Some Kind of Monster" because they don't like the album St. Anger but I really believe that it caught Metallica at a vulnerable and revealing time in their history. (https://www.netflix.com/title/80174429)
Searching for Sugarman: https://www.imdb.com/title/tt2125608
Don't Think I've Forgotten: https://www.imdb.com/title/tt2634200