The BBC music documentaries are well worth watching. Synth Brittania explores the roots of synth music in the U.K. (interviews include Kraftwerk, Cabaret Voltaire, Human League, Gary Numan, etc.). Hawkwind documentary is essential. Krautrock program includes interviews with Faust, Klaus Schulze, Amon Düül II, Can, Harmonia, etc. You can find them on Youtube or torrents.