It always surprises me how quick so many folkies are to impose rules; if there is any form of music that should be free of these types of restrictions, it is surely folk music.

I write a lot of songs, and I'm generally pretty proud of them. Some come very easily ("out of thin air," seemingly), others require a lot more labor on my part. If someone improves on them, great; if someone takes them in a less positive direction, that's unfortunate, but I will just hope that the higher quality version (mine, perhaps) will ultimately prove to be more durable. I think people should feel free to exercise their creativity in music, including reworking music and lyrics as they see fit. From a legal perspective, I want control, credit, royalties, and anything else that is my due for having written the song. But beyond that, I don't want to hamper someone else's creative vision, whether he is a songwriter or interpreter. There's plenty of room for alternative versions of any and all songs.