Right now, I don't think it will be there for long, is the excellent 2013 music documentary "Muscle Shoals". Aside from the fantastic history that I was unaware of, the filmmakers did an outstanding technical job. This is one not to miss.
I found it fascinating to learn about the people behind the music sound of the late 60s and 70s. Plus, I lived in the general area of the country at that time so it was even more fascinating.