I've been thinking about Cecil Sharp's statement, that a folk song is always anonymous. Probably, in his time, and considering what he was collecting, that would be true. He was collecting from non-professionals, i.e. folk singers!
If his research turned up an author, then he could reclassify it, according to his lights.
And back we go to the unanswerable 'What is a f.....

Aaaagh.