Turning Rick Astley into a Nightmare Fairground Soundtrack
Run a Spectrum Analyzer against Rick Astley’s hit track “Never Gonna Give You Up”, and you’ll get an image of the frequencies used in the song; a sample of such an image is shown above (Side Note: Does this violate copyright? You can reconstruct part of the song from it). This particular analysis was conducted with the beautifully named open source package ARSS.
Anyhow, the great thing about this is that you can then manipulate the image in Photoshop, then convert it back into audio. Flip the image horizontally, and the audio plays backwards. Remove a horizontal strip from the image, and a chunk of frequencies disappear from the track.
With a bit of contrast screening and vertical-flipping, converting the image back into sin-waves produces the following Lynch-ian nightmare soundtrack. All from such a sweet song.