" "Wild Mountain Thyme," but it is not remotely "folk."
The song is an excellent example of how a written and published song can become part of an oral tradition - I suggest you dig out Elizabeth's Cronin's 'Braes of Balquidder' to see what I mean."

Yes. I had met "Braes of Balquidder" (in a book) before the sixties. Quite likely, (and I expect I am speaking heresy to you now,) as the daughter of a schoolteacher, Elizabeth Cronin got the song from a book too.

But here the divergence of planes that I mentioned earlier. I can appreciate that "the oral tradition" is of great importance to you and others, but I cannot feel in my guts that there is any great difference in moral quality, as it were, between oral/aural transmission and other kinds. The first "real" folk song that I can remember hearing was "Richard of Taunton Dean" sung by an old fellow in a pub in Devon - not in a folk club, just the usual village crowd gathering round the piano on a Thursday night, (their favourite was "I'm forever blowing bubbles.") Later on, I learnt the song from "The Oxford Song Book." Much later on, I realised that my copy of "The Oxford Song Book" was older than the old fellow (well he was older than forty anyway) who had sung the song. Did he learn it from a book or his granddad? If someone learns it from my singing, is it back in the oral tradition? Does it matter?

Fifty years on, I agree that "Wild Mountain Time" in the McPeake version, has probably entered the oral tradition and might be classed as "folk" assuming that one can admit that the sort of people who go to folk clubs are "folk."
At the time, however, I felt that McPeake had thrown away the truly folk part of the song, kept the art part and added a new part. I did not appreciate that he had copyrighted his arrangement as well, but had I known that it would have confirmed my view that it was not folk. Whether anything with a known, and living, author can be "folk" is an old and fruitlessly debatable point, but it definitely can't be "folk" if you are denying folk free use of it.