Jim wrote -
'It's been up several times Vic, but 'yer 'ttis again:
""If 'Little Boxes' and 'The Red Flag' are folk songs. we need a new term to describe 'The Outlandish Knight'. Searching for Lambs' and 'The Coal-owner and the Pitman's Wife'."
Thanks very much for that, Jim, very helpful. It comes from page 410 of Bert's Folk Songs in England. I'm glad that when I asked you this at 11 Jul 18 - 10:21 AM I also wrote asking for "the context he said it in." because if you look at page 410 the sentence that follows the one that you quote above says:-

In any case no special mystical virtue attaches to the notion of folk song, grand as some folkloric creations may be.

Now, I am paraphrasing here, but I take this to mean that Bert is saying that folk songs do not have a unique quality and yet you have written:-
at 11 Jul 18 - 08:54 AM
Sorry Vic - you (and everybody here) is ignoring the uniqueness of fok songs..... what are we going to call this bunch of unique songs - or maybe they are not unique
and at 11 Jul 18 - 02:22 PM
If you don't accept that out folk songs are unique, I don't thin we have a point of reference between us

I am starting to think that we actually do have a point of reference here an that we are getting somewhere, but it is foundering on your use of the word 'unique' to reference to folk songs. We need to know what you mean by using this word to describe folk songs.
When you were asked:-
"Can we tell anything from the style of language?"
You replied:-
Absolutely - the familiarity with vernacular usage says much about the songs as does anything else - as does folk humour
....but it cannot just be the vernacular because that abounds in Music Hall songs and you would exclude these.
Can you see that if we are to make progress (and I feel that are getting somewhere) that we need you to tell as what in your thinking is unique to folk songs - a quality that is not found elsewhere.