[LAU] Create A Negative of the sound

Hi, Is there any software that can create a negative of the sound? I'm thinking of taking an arbitrary frequency bandwith, pick a center and invert it, so that bass becomes high, and high becomes bass? I have the feeling this is an impossible task due to the nature of sound. But i dreamed it up last night, so it HAS to be possible somehow, if i can trust the comic books of the fifties containing TabletPC, space-rockets and wireless phones. :D In the dream, they would use some software similar to the ones used to remove noise from audio, where you see an abstract colour representation of the sound, and you can kindof "paint" out the undesired noise. Then they would just, flip the coulours arround. We first listened to a drum track (in the dream, yeah?), and the highhats would sound like kickdrum and the kickdrum soundet a bit like highhats. Then they applied it on the entire song track (still in a dream ok) and it sounded so good that my enthusiasm woke me up... Thankfull for any explanations and ideas, Yours dreamfully, -- Set Hallstrom AKA Sakrecoer http://sakrecoer.com