I think we have reached a consensus on "Folk" tunes:

.........the role of tune books has a very long and central history in the survival and evolution of English dance tunes.

One of the earliest publications was "The English Dancing Master" published in London in 1651 by John Playford. This volume contained the figures and the tunes for 105 English country dances and a number of the tunes first published there appear in our collection.

Across the intervening 350 or so years thousands and thousands of tunes have survived and evolved because people enjoy dancing together on social occasions and because they are great little tunes. Some were printed, published and sold in collections and some were written down with pen and ink by musicians for their own personal use. Sometimes musicians played for grand balls, dressed well and lived a good life. Others played elsewhere on the social scale. The tunes have passed back and forth between those who could 'read' and those who learned and played 'by ear'.

Has the journey for "Folk" songs been much different?