Perhaps we should make some base distinctions? Song altered by a traditional singer UNDER THE INFLUENCE OF A COLLECTOR/REVIVALIST (e.g. Geogrge Dunn supplied with broadsides by Roy Palmer, Joseph Taylor entering FSS competitions). Songs adapted by a non-student traditional singer(Harry Cox, Walter Pardon) or by a student traditional singer (Bob Roberts, Bob Copper, Bob Lewis). Songs adapted by a traditional singer/professional musician (Charlie Bate) (first define traditional singer! - first define professional!) Songs altered by collector/revivalist (Sabine Baring-Gould, Cecil Sharp, Bert Lloyd, Martin Carthy, Nic Jones).

Ultimately, surely the interest is in where transition takes places, and why, and whether the listener is being decieved - intentionally or otherwise?

Tom