Sorry, Dave, but it depends on your definition of 'recent'. Given the the length of time the music has been around, then Sharp's activities were like yesterday. The obsession with definitions only started once the academics got involved.

And if Sharp 'knew' what a folk-song was then where is his killer definition?

And if Child 'knew' it didn't include broadside ballads then he was wrong, wasn't he? Because some folk-songs did end up on sheets. Indeed, in a few cases the broadside version is the only source.

If you read what the singers themselves said, you'll find that most of them referred to the material simply as 'the old songs'. No fancy definitions there. No need.