Also interesting that the early MacColl records featured jazz players like Bruce Turner. And of course if you followed the career of trad jazz banjo player Lonnie Donegan you learned a hell of a lot of folksongs.

It would be interesting to know at precisely what point it started, this disdain for and rejection of this kind of music - that in 1961 or thereabouts seemed like an integral part of the English scene.

I don't think the rejection and disdain was totally from the folk world - see the attitude of the rocker character Jim Maclain towards jazz in the That'll be the day film. It is hinted that jazz is middle class - joe college stuff. Also this was a theme in John Mortimer's Leslie Titmuss plays. Apparently The Cavern was a trad jazz club just prior to The Beatles coming on the scene.