iplayer has 4 episodes of "the Devil's Music" at the moment, a series on blues first shown in 1979! First episode includes Sam Chatmon and Bukka White, great stuff. It's really good to see a programme that shows you the whole song instead of a new sound clip and crazy camera angle every 10 seconds. Apologies if this has been posted before but couldn't find it.
http://www.bbc.co.uk/iplayer/episode/p00lk3lz/The_Devils_Music_Series_2_Episode_1/