Harker states that Child’s theory was influenced by three main people: Sir Hubert Parry, Carl Engel, and Francis Barton Gummere.

1 Parry taught at the Royal College of Music and wrote a choral used at Coronations, and the music for Blake’s ‘And did those feet in ancient times’, though I don’t think he understood Blake’s bitter irony and I’m certain he would not have liked Blake’s politics. Sharp had ambitions to be an art musician and did use ‘folk’ music he had collected in his ‘art music’ as did others of his time of course.

2 Gummere is lit focused, not a musicologist. He had ideas about the origins of music and dance.
Examples of his style and of what for me is somewhat evidence-free theorising are here:
https://www.bartleby.com/library/prose/2028.html

Harker says Sharp took his three-part account of ‘folk’ from Gummere, the three elements being a) continuity b) variation and c) selection. Harker regards Sharp’s theory as social Darwinist; presumably Harker would prefer a more Marxist account of this history of song, such as in A L Lloyd but less ‘vulgar’ to use Harker’s expression.

3 Carl Engel is the only one of the three I had never heard of before reading Harker so yet again I learn something. One of his specialities was ‘national musics’, and we know that producing ‘national music’ of a sort that could be taught to children for example was something Sharp was especially interested in.

For more on Engel, see here:
https://babel.hathitrust.org/cgi/pt?id=coo1.ark:/13960/t3223gm0x&view=1up&seq=19

I thought this background was interesting, but would be interested to hear whether other posters feel that Harker is right in highlighting these three and so on.

Put together they would help explain why Sharp went looking for folk song in bits of Somerset that he regarded as full of ‘peasantry’, (to anticipate a discussion of Bearman which may or may not take place here). For as Harker points out, he did not go to Bath, Shepton Mallet, Taunton, Bristol, Yeovil etc etc. And while it is true that Sharp’s notes incude much that he did not publish, and that this material has been useful to people coming after, I think that Harker is claiming that Sharp might have/did ignore stuff that people were singing that he, Sharp, decided was not folk. In that Harker includes as a possibility songs in the modern minor (melodic presumably) as opposed to the modal material that I personally know Sharp was fond of noting and remarking upon. I think Harker is keener on accounts that are more fully representative of actual ‘working class’ culture as a whole as it existed.

So this is my attempt at seeing the background against which to think about what Steve said in his last couple of posts. Happy to be corrected if wrong. Hoping this is a constructive if long contribution to the thread.