The Keaton Music Typewriter, first patented in 1936, definitely doesn't look like a regular typewriter! The 14-key typewriter (later upgraded to 33 keys in a 1953 patent) was sold for about $255 in its time.
The unique keyboard arrangement was born of a desire to separate two types of characters. “One keyboard is adapted to type one class of music characters such as bar lines and ledger lines, which, when repeated, always appear in the same relative spaced positions with respect to the [staff] lines… and a second keyboard adapted to type another class of musical characters, such as the notes, rest signs and sharp and flat signs etc., which may, when repeated, appear in various spaced positions with respect to the [staff] lines,” Keaton wrote.
Image Credits: Marcin Wichary