This is a pretty cool gadget I came across on the internet, it's a Music Typewriter that was first patented in 1936 by Robert Keaton from San Francisco, California. It pretty much does what you'd expect from looking at it, types music notation on a sheet of paper lying under the typing mechanism. There aren't many Keaton music typewriters and most are in museums and private collections. It was marketed in the 1950s and sold for around $225.
I feel like even for a musician this would need a particularly minded artist, thinking about music like this is definitely a bit foreign but it'd be a lot of fun to mess around with.
