pfft~ for independent pitch processing?

Hello

Does anyone have ideas on how to modify the pitch of a sample independently of time i.e., change the pitch without speeding up playback? I'm guessing I would use pfft~ to modify the spectral information but I can't find anything in the manual that demonstrates how to do this. I'm sure I'm not the first to ask this so if anyone knows of a good algorithm I would be most interested.

Thanks,

J