The left , both in Britain and the U.S., put folk song into the public gaze
In Britain, the earlist moves were by the Workers Music Association, who inspired Topic Records and MacColl and Lloyd.
Both Ewan and Bert took their leads from Alan Lomax, who was on the run from MacCarthy's witch-hunt.   
Immediately, they recognised folk music as the creative art of 'the common people' (rotten term, but it sums up who I referring to).
When I came on the scene at the beginning of the sixties, the clubs were full of working class youngsters - I (an apprentice of the docks) went to my first club with mate, who was a porter at 'Paddy's Market'.
The scene was pretty much the same at The Singers Club and in Birmingham and Manchester then.
Maccoll commented on the time he aand Peggy was booked at Doncaster - the room was full of steelworkers - "all shouting, because they spent their entire working day in the noise of steel-mill machinery.
Those of us who got involved in research continued to recognise it as 'people's music' - though it is noticeable that, since the 'anything goes' attitude has grown in the clubs, coupled with the risde in the number of singers who associate singing with being paid, the more conservative (with a small "c") and middle-class the audiences have become.   
I'n not making a general rule for this - many clubs I continued to go to still attracted working class audiences.
Jim Carroll