The ANS synthesizer, imagined in 1938 and built in 1958 by Evgeny Murzin. It is controlled by glass discs that have the arrangement printed on them. It was used most notably on the soundtrack to Andrei Tarkovsky's film Solyaris. A curious fact is also that this thing is 720-note (or should I say pitch) polyphonic!
Also worth checking is this interesting article on the ANS.
Update: now a virtual version of the ANS is available for everyone to play with!