This is a demo of mikerotondo‘s Stompolin:

When the guitar is too sexy and the piano makes too much sense, it’s time to stick a bunch of sensors to your body with electrical tape and plug it all into your computer!

via mikerotondo:

This is the Stompolin, and I made it at a Physical Interaction Design workshop at CCRMA (http://ccrma.stanford.edu) this summer.

How it works:

There’s a small electret microphone attached to my foot, and two bend sensors on my arm: one in my elbow, and one on my finger. The signals from each of these are routed through an Arduino microcontroller into a Max/MSP patch.

The microphone output is routed through a percussion follower, and impulses (like stomps) trigger the instrument’s tone generation. The sound of the instrument is created by a a plucked string model and some ADSR’d harmonized sine waves. If the impulse picked up by the mic is heavy in high frequencies, the sound is captured and “granulated” around a bit at a random interval.

The bend sensor on my finger controls the pitch of the tones, and the elbow controls the cutoff frequency of a low-pass filter. When the pitch is being actively modulated by finger movement, the tone slides smoothly across frequencies, but when the finger is moved more slowly or stopped, the pitch is quantized to tones of a major scale.