My good friend Moby pointed this clip out to me, I'll let him summarise:
in 1939 billie holiday was a huge pop star and she wanted to record 'strange fruit', a song about racism and lynching, and her label wouldn't let her.
so she recorded it for a tiny indie label and it went on to become her biggest selling record.
it's regarded as the first recorded protest song, and this performance of it is one of the best things i've ever seen.
- moby