Sometimes it is just as well to say "sue and be damned." That is what I would say if I was running one of those festivals. That is generally what newspapers say when they get such threats -- usually daily. I know what I would do if someone came into my barbershop and demanded money for me playing the radio. The gentleman in question would have a quick shave with the clippers.

I am not knowledgable about copyright law, but I thought that in Canada and the US no-one could refuse permission to sing or record a song. Insist on royalties when recorded, yes, but not refuse to allow its use. I thought that was the whole trade-off with the copyright laws.

I also think it can be short-sighted to insist on royalties from live performances, as opposed to recordings. If people get to know and like the song, they might buy the recordings where royalties are payable. A strict attitude reminds me of Hollywood in the fifties, when they saw television as a threat to the movies and wouldn't let them play movies on T.V.

On the other hand, some performers write songs which end up being recorded as "traditional" by others. I have seen "Cape Breton Lullaby", written by by the poet Kenneth Leslie and still in copyright, listed on a CD as traditional even though it first appeared in print and was recorded in the 1960's. (I e-mailed a complaint to the artist, but got no reply.) Fiddler's Green, The Dark Island, and Margaret's Waltz are other tunes often assumed to be by that great and generous composer, Trad Anonymous.