The Keaton Music Typewriter was first patented in 1936 (14 keys) by Robert H. Keaton from San Francisco, California. Another patent was taken out in 1953 (33 keys) which included improvements to the machine. The machine types on a sheet of paper lying flat under the typing mechanism. There are several Keaton music typewriters thought to be in existence in museums and private collections.
It was marketed in the 1950s and sold for around $225. The typewriter made it easier for publishers, educators, and other musicians to produce music copies in quantity.
Stopped by an antique market this afternoon and fell in love with this. I had to tear myself away when I started daydreaming about buying it and typing letters and shit. I really have to curb the impulse buys.