The Gauss-O-Phone is a new musical instrument played with the finger(s) of one hand and a magnet held in the other. At the same time, it is a computer-generated musical piece that allows the user to play along with it and solo over it, while it selects its next key changes based on what the user plays.
The construction of it is incredibly simple, just a position-sensing strip along the length (which responds to the user’s finger) and four Hall effect sensors (which respond to magnetic fields) at one end. The magnetic sensors play the root, fifth, third and seventh (minor or major, depending on what key the user is playing in) of a chord determined by the position of the finger along the strip. It’s a lot simpler to play than it is to explain.
The computer program generates a drumbeat and a bassline randomly and probablilistically, and then changes keys based somewhat abstractly on what the user plays. The backing track is definitely a dice-roll – sometimes the computer comes up with something wonderful, and sometimes it sounds deeply silly or just plain wrong. It’s also possible to turn off the backing track and just play the instrument, which was what users seemed to enjoy most anyway.
Further explanation can be found here: