The Chipmunks were born in 1958. Ross Bagdasarian (under the name David Seville) recorded a novelty song, "Witch Doctor," using sped-up vocals to imitate the chants of the witch doctor. Later that same year, he recorded "The Chipmunk Song," utilizing the same process, but this time identifying his sped-up vocals as Alvin, Simon and Theodore, the Chipmunks. Later he re-recorded "Witch Doctor," with the credit, David Seville & The Chipmunks.
BTW, Bagdasarian played the songwriter in Hitchcock's Rear Window.