On January 28, 1969, while The Beatles were rehearsing Old Brown Shoe, John Lennon brought out a Stylophone. A Stylophone is a miniature synthesizer, introduced in 1968. It works by tapping the dummy keys with a stylus, which activates the note. As you hear in this video, it's got a very buzzy tone. The Stylophone is probably best known for its use in David Bowie's classic "Space Oddity".