Good BBC Radio 4 program, you got 8 days to hear it at this location:
http://www.bbc.co.uk/programmes/b00g3yqn
"Writer and broadcaster David Hepworth charts the story of secret recordings, artist out-takes and demo tapes that make up the world of the bootleg."
Various points of view covered, and a wide range of music.
There's no mention of Hawkwind, but of course Peter Grant's baseball bat gets mentioned! That story was on my mind a bit, back when I taped Hawkwind in '76 and '77, and I never imagined that, one day, distribution of those tapes would be tolerated by the band. So they remained undistributed until Jan last year!