Not sure if it has been mentioned, but the standard (and seminal)
work on the sounds that accompanied silent film is the tremendous book,
"Silent Film Sound," by Rick Altman (Columbia University Press).

It's out in paperback now and covers all kinds of music, mechanical
and otherwise, that that was used to accompany silent film.  It's a
fascinating history, lavishly illustrated and thoroughly researched.
(Full disclosure, I was a consultant to the author.)  Information is
here:  https://cup.columbia.edu/book/silent-film-sound/9780231116633 

David Kelzenberg