Tree of Liberty is an excellent suggestion! It looks at The Songs of Robert Burns project of Serge Hovey, features Esther Hovey, Jean Redpath, Lynn Shevitz and others - Hamish Henderson made some of these connections for Serge, helped him source the original tunes lurking in libraries in Edinburgh...
Sadly every single person I just listed (apart from Tim!) has now passed away, so the documentary is even more of a treasure.
(all of Tim Neat's books, films and artworks are worth seeking out)