Randy, I got my information from this webpage...http://www.woodpecker.com/writing/essays/royalty-politics.html
I can't vouch for all the accuracy of it.
I do think that forcing a small venue to pay royalties when a)the music is primarily in a jam format and no one is paid and b)much of the music is traditional in nature and playing it does the service of keeping it alive in the culture, is the sort of thing that discourages live music in an acoustic format, and that is the foundation of the music most on this Forum love.