Behold the neatest typewriter you'll see today: the Keaton Music Typewriter
that types musical notes on blank sheet music.
The typewriter is so rare that less than a dozen are believed to still
exist (and you can get one for a mere $6K on Etsy): Link
- via Notcot
Now this is a rare and expensive typewriter:
http://www.typewritermuseum.org/collection/index.php3?machine=hansen&cat=kd