The Tradition is only a backwards projection of The Revival. It didn't exist before The Revival said it did

[mimes cranking motion with right arm]
We were here only yesterday, but since this wild statement has surfaced again on this thread, could you now clarify what you would call the domestic, participatory singing culture, handed down through generations, that existed before the Revival did, and why the word 'tradition' is inappropriate to describe 'that which is handed down'. Or do you just mean it in the sense that a cat is not a cat until somebody calls it 'a cat'?

One wonders how the Old Modal Song & Ballad Idioms might have fared had they not been so favoured by the Colonial Revival, or if The Revival had never happened

I'm not sure what 'the Colonial Revival' is (I presume you've invented the term) but I guess they would have gradually died out in England over the course of the 20th century as the singing tradition itself died out, but possibly have lasted better in the Appalachian mountains (although Sharp's collection casts a long shadow over there too). Others can speak for Ireland and Scotland.