My focus has shifted, temporarily. I've been looking at a couple of collections of national songs from the late 18th century - the Thompson family's Caledonian Muse and Hibernian Muse. (Try as I might, I haven't yet found a Cambrian Muse, but next time I'm in London, there are sources I need to check, just to be sure!)
The Thompson family were at the sign of the Violin and Hautboy, 75 Saint Paul's Church Yard, in London.
Meanwhile, Joseph Johnson, a politically radical literary publisher - he also published Non-Conformist church literature, and encouraged women writers, too - was just three doors along at no.72 Saint Paul's Church Yard. I've discovered an unexpected connection between the two. I'll be writing more about this in due course, so I am going to be irritatingly secretive for the next wee while!
To my joy and delight, Hilary Chaplin, a historian and music-lover who tweets @hilaryssteps, has been tweeting pictures of old London, and generously found me a wonderful etching of St Paul's Church Yard just a couple of decades after the events I'm interested in. I love to be able to imagine "my" musical and publishing ghosts in their natural environment, so I'm delighted to share this picture. Hilary tells me that in the foreground, people are looking out of Bowles and Carver's Print shop. They were at 69 St Paul's Church Yard - incredible, just literally a couple of doors away from "my" people. Oh, WOW!
Thanks for your help, Hilary!