I'm playing with Audacity, an audio editing program. One of its features is the ability to change pitch without changing tempo...Think a digital version of Alvin and the Chipmunks.
...or go the other way with an Abba song....I turned the pitch to 30% low on "Take a Chance on Me" and the result is bizzare. The pitch of the female shifts to a male tone, but the inflection doesn't. Here is about 15 seconds:
(Sorry for the sound quality--too many conversions between formats)