This is a toughie for me. There are some folklorists who would have us put a halt to the folk process. People who study the various versions of a song and write them down in a book so no one may ever again change them and possibly start the process of creating a new variant. I've never run into one of these people in real life - only encountered them on the internet.

One thing that does bother me is when people intentionally change a song simply to put their stamp on it. They don't make it any better, and their purpose seems simply to say "I Am." Please note, this isn't the same thing as changing a word to make more sense or adding something that seems to be missing - people do that for the sake of the song, not their egos. No matter how irritated, insulted, or downright indignant I or anywone else gets, in the end, the only thing that matters is what people sing. The more choices there are, the more chance a song has for survival.

If the song doesn't ever change, it ain't oral tradition.