"In the chapter on 'Back-street printers, ballad sellers and buskers', the '90-95%' figure for the number of folk songs appearing in street literature is on p 442, and although SR does enter the caveat that this is not in itself evidence of a direct link, other evidence suggests to him that there is."

OK, that's the chapter I'm currently reading. I'll look out for that. But I did use the word "originated" - not "appeared". Just because a song appears in a broadside, doesn't mean it was written for that broadside. I mean, I know that 'The Streams of Lovely Nancy' was printed on a broadside, but it seems hard to imagine that a broadside writer would have consciously sat down and penned so many non-sequiturs.

So I'd be interested in the evidence behind: "probably written by ... broadside hacks" too – as I can't really imagine what that evidence would look like. (Given how, as Roud points out, broadside printers nicked each others' material.) I wonder what percentage of broadside songs have known authors?

Just to clear, by "folk songs" here, is Roud referring to songs he's given a Roud Index Number to – all the folk songs he's ever come across? Is he saying 90–95% of the folk songs he's ever encountered have appeared in street literature?