The job of creating voices for Munchkins and Winkies in The Wizard of Oz fell to vocal arranger Ken Darby. “In those days we didn’t have the technical facilities we have now, like speeding up tape,” he said. “I had to figure out how to make the Munchkins sound high-pitched”:

I worked it out mathematically, using a metronome. Then I went to the head of the sound department, Doug Shearer. I told him that if we could record at sixty feet per minute instead of the normal ninety feet per minute and if we sang at a slower pace in a different key, when we played it back at ninety it should sound right. He said there was no way to do that because we didn’t have a variable-speed recorder. Then he said he would try to manufacture a new gear for the sound-recording machine. And it worked. I had the singers sing very slowly and distinctly so the words would be clear when we played it back at a faster speed. Ding … Dong … the … witch … is … dead. When we played it back, it was a perfect one-fourth higher.

“None of the midgets did any of the singing. None of them could carry a tune.”

(From Aljean Harmetz, The Making of The Wizard of Oz, 1977.)