Music Documentaries from the Classic Era

I'm seconding Bill Green's recommendation of the Standing in the Shadows of Motown documentary. Great historical footage and interviews interspersed with the players - The Funk Brothers - backing up contemporary singers doing some classics.

Another excellent music doc is Tom Dowd & The Language of Music, focusing on the recording engineer who created the 8-track console at Atlantic Records while working with players like Ray Charles, Aretha Franklin, Otis Redding, John Coltrane, Dizzy Gillespie, Thelonius Monk, Cream, Rod Stewart, Lynyrd Skynyrd, The Allman Brothers Band, Dusty Springfield, Clapton, Cream, Derek and the Dominoes.