The Keaton Music Typewriter

A typewriter has filled the void between handwriting and typesetting for about two hundred years now, but there's plenty of other things besides just letters and numbers that need ink on paper. Here we have one such example — the Keaton Music Typewriter:
This particular example is for sale on Etsy, with a $6,000 pricetag — definitely worth the money, since there are only a few left in existence. The Early Typewriter Collectors Association has an excellent article on this mechanical musical typewriter, too. If you want to figure out how it works, you can see Mr. Keaton's original patent online.