"Jim's definitions usually seem to be framed so as to include the works of Ewan Maccoll etc"
I don’t have a personal definition, folk song is far too well defined for me to need one
Take on folk song is pretty well those that launched the revival way back in the early fifties and kept the scene alive into the late eighties
I don't need a 'definition' to know what folk song is - it is what i says it is - the music of the folk that kept the songs alive for centuries and probably made most of them in the first place - the farmers, sailors, soldiers, land labourers, factory workers, poachers, transportees.... all substantiated in the repertoire as the 'folk personnel'   
If you don't know what folk song is - go read one of the many hundreds of books that have ben written on the subject - in Britain, in America, Scandinavia, Easter and Western Europe.... wherever folk song has been art of people's lives.
I liked what MacColl did to folk songs and loved the way he used folk forms to create new songs - I am still in awe of the masses of research he dos on understanding and performing folk songs - latterly with The Critics Group
All this has nothing to do with my defining what folk songs is - I knew I was on to something unique and important shortly after I walked though the door of my first folk club at the beginning of the 1960s - and what was more important, so did thousands of others like me who filled the clubs - in Liverpool, Manchester, London - and all the other places we put our selves about to go and listen to folk song - we knew what folk song was when we opened up our copies of 'The Penguin Book of English Folk Song - that remains the good introductory collection it was when it was first published in 1959 (an Lloyd's Folk song in England remains the magnificent inspration study it was when it was published around a decade later)
The clubs began to fall away when it became to leave a folk club without having heard a folk song, or anything resembling one - when they became cultural dustbins to throw in anything they couldn't think of a name for

I know what folk song is and can spend hours talking about is (as I have down the years)
If it has suddenly become something else, somebody needs to tell us what it is and quick, before it is lost to us altogether
This faffing around a sprinting off at the rate of knots whenever 'definition' is mentioned is going to do more damage than it has already done - if that were possible
Your starter for ten - What do you people think 'folk song' means
Jim Carroll