If you are interested to see things in something of a bigger picture I don't think scholarly works like that of Harker are the place to go. You need contemporary descriptions and accounts. Scholarly works may include pointers to them in the references they give but that is not what the scholars or their publishers are about.

The bigger picture is going to be spread out over a vast amoiunt of writing elsewhere, much by amateur experts who are interested in digging out details and writing for people who are interested in them.

We used to have about 15-years worth of Folk Music Journal in the house. I now only have four numbers that had been mis-shelved at the time we gave them away. Those include an interesting 1988 article by Vic Gammon, which starts "Reading through nineteenth-century copies of the Sussex Agricultural Express as part of my research project on ...", a 1992 article by Dave Harker that has a lot of 17 century detail, and a short 1989 note by M G Myer quoting extracts from a correspondance with Bob Copper about why the Copper family repertoire didn't include Jack Tar/The Saucy Sailer though his grandfather sung it (which has parallels with things Walter Pardon is quoted as saying).

As can be seen in his extensive references to Alfred Williams, Harker does dig into the historical context of the songs and singers. That's not what 'Fakesong' is about. That is maybe why this discussion keeps going off topic in interesting ways.