Frederick Sammis invented the “singing Keyboard” in 1936, a precursor of modern samplers, the instrument played electro-optical recordings of audio waves stored on strips of 35mm film.
Let us suppose that we are to use this machine as a special-purpose instrument for making “talkie” cartoons. At once it will be evident that we have a machine with which the composer may try out various combinations of words and music and learn at once just how they will sound in the finished work. The instrument will probably have ten or more sound tracks recorded side by side on a strip of film and featuring such words as “quack” for a duck, “meow” for a cat, “moo” for a cow. . . . It could as well be the bark of a dog or the hum of a human voice at the proper pitch.
(Frederick Sammis, quoted in Rhea 
‘The Computer Music Tutorial’ Curtis Roads
Invention and Technology Magazine. Mathew Nicholl. Volume 8, Issue 4. 1993