Jim, there is a difference. When a traditional singer gives a song to a collector it has cost him nothing (please understand I am not denying the singer's creative effort involved) and he is losing nothing except the opportunity to exploit it for himself. Someone who produces a CD has invested a substantial amount of money in recording, mastering, producing, packaging and distribution, including paying fees for copyright where appropriate. There is a clear and immediate financial loss when someone else gives this work away for free.

I entirely agree with you that the exploitation of source singers is an appropriate subject for discussion. However, in the context of this thread I think it is a distraction. SOP's argument, if I understand it, is that because material was "plundered" from the traditional sources (itself debatable) then its being plundered in turn by music sharers is justifiable. I don't believe that's a valid argument.