Here’s a very successful circuit bent casio I did, the rapmaster, I tried to give it a nice color scheme and provide it with a glitch pot and the most interesting part, a feedback pitchshifter.The rapmster originally came with a microphone and a very basic lofi pitchshifter effect, this was abused in the eighties by kids holding the supplied microphone too close to the speaker. I internally fed the pitchshifter back into itself, creating a crude, but useful pitchshifting delayline.
[audio:rapmasta_demo.mp3]Extra info on the electro music forum.