> All the early anthologists tampered with the songs.

All traditional informants alter their songs as well, usually unconsciously and trivially, but sometimes otherwise.

Much of the editorial "tampering" (which, as I say, is a needlessly tendentious word)came not from hidden agendas and a disposition to fraud, but from a naive belief that "improvement" brought the lyrics closer to an aesthetic ideal which, by another leap of faith, the presumably lost ur-text must have approximated.

The early editors, on the one hand, saw the ballads as flawed but precious artworks, not as contestable social artifacts.

The broadside printers saw them as a source of income, and if lengthening them ad lib might boost sales, why not do it? (I'm not accusing the usual suspects, just stating the principle.)