As the website's section on Cylinder History says - "From the first recordings made on tinfoil in 1877 to the last produced on celluloid in 1929, cylinders spanned a half-century of technological development in sound recording. As documents of American [and other countries'!] cultural history and musical styles, cylinders serve as an audible witness to the sounds and songs through which typical audiences first encountered the recorded human voice."
It's a gold mine of a collection - another route into the feel of the times for historical novelists and readers alike - but there are some problems attached to this sort of research. I dare you to listen to this, for example, and not have that chorus stuck in your head forever. Clearly that's what has happened to Thomas Edison below
Chirpy Cheerful Thomas Edison 1888
The lovely lady in the picture (whose name may very well have been Mabel) has her delicate pinky dangerously close to the recording surface - see below for the correct way to hold a cylinder!
(Long before I knew about the Project, I found this wonderfully scratchy recording of the Ride of the Valkyries on Wikipedia and used it as the backing track for a trailer for The Mucker's Tale - not one of my most serious or, for that matter, historically accurate books, but you're welcome to come over and have a listen here!)
Joan Lennon's website.
Joan Lennon's blog.