The Latest Insanity Generator... Here's a birthday present for my long-time buddy (his birthday was in November). It's a touch-sensitive synth built into a little guitar I bought for 100 pesos in Tijuana. It's triggered by tapping on the piezo element sealed underneath the penguin, runs for however long the decay is set, and can be modulated in different ways merely by touching the the strings... with HUMAN TISSUE !!!!!
Controls are volume, decay time, and amplitude modulation vs. frequency modulation. The last switch patches the body contacts between the main "pitch" oscillator, and the modulating "freak out" oscillator. Check out the waveform.
It took a lot of trial and error and screaming and error and error and trial to get the piezo sensor to work consistently. The other big thing was actually electrically isolating the strings from each other so that they would respond to TOUCHING and nothing else. This was done by wrapping the base of each string in plastic tube, and sealing the metal frets with an acrylic glue so they don't short out when you push the strings all the way down.
So now Jon, his seven pet monkeys, and his dog taco have a guitar they can make beautiful music with simply by cuddling with it.