George-

Even Ewan MacColl agreed that the folk process was an ongoing process and that he himself engaged in it. Some are better that others at making changes that others accept as "improvements" but only time will validate that appraisal.

I do believe it is important to have reference material so one can see how a song has evolved, and that the various folk song collectors should be thanked when they did their job well, and damned when they edited their source material.

Cheerily,
Charley Noble