Folk music and "the commercial" can walk past each other or interact at their edges without confrontation.

Yes, except, and I think it is a topic for another thread, is it possible to draw a line between the two? Jim gives an account of a Traveller getting songs printed up for selling at fairs. Is that Folk music or commercial?

I am just reading Keith Summers' "Sing, Say or Pay!" and notice an anecdote - Percy Richardson:"I was 17 when I started and I did it till 1932 when I married. We used to buy the News of the World for tuppence and they had songs in them. My poor old mother used to stitch them to pieces of brown paper for us." What's more important, where the songs came from or what "the folk" in a Sussex pub actually did.

I got onto that because before I was going to point to Peter Kennedy's 1955 film from the Blaxhall Ship as an example of the inevitability of resource limitation leading to 'mediation'. The finished film is only about 20 minutes (so a time limitarion) and it looks like it was made with a single camera, so to keep each song complete we get the atmosphere of the pub from "B roll" pictures that don't fit the sound we hear with them. Similarly there seem to be edits at the beginning and end of some of Alan Lomax's published (so a time limitation) recordings at the Ship to get some 'atmosphere' included.