After hundreds of densely packed pages on folk song in England — a subject for which I share Steve Roud’s passion — I am none the wiser as to why folk song collectors assumed that a man singing in a pub for free drinks in, say, 1890 or 1920 was de facto a folk singer? A singer of folk songs, yes. A folk singer, maybe not. Such men were ‘professional’ singers of popular songs. They sung what people wished to hear, for recompense: a pint.
If a collector was lucky — and they often weren’t — he might hear on a particular evening the weal and woe and muck and mire of ‘auld ballets’, but they would be buried amid what the 19th-century ballad editor Francis James Child called ‘a veritable dunghill’ of broadside ballads and music-hall pastiches [ . . . ] More at: The vibrant tradition of English folk song | The Spectator