Musician-turned-creative-coder Aaron Sherwood describes his latest project as a "sound sculpture." And after taking just one look at the Magnetophone (or better yet, listening to it), it's clear that the term is justified. Sherwood began playing music professionally at age 15, but in more recent years has focused his efforts on art. Last year he created Firewall, an interactive membrane surface with stunning fire-like visuals. But the Magnetophone — not to be confused with the reel-to-reel tape player — may be his most impressive work yet.

It features 14 guitar strings and 14 homemade electromagnets, with continuously generative, electromagnetic fields that cause those strings to vibrate. Measuring 3 feet tall, it's made primarily from aluminum and acrylic. (Sherwood started out with plywood, but said the result looked "too much like a grandfather clock" and didn't meet his goal of making Magnetophone "look less like an instrument.") Guitar strings of various gauges run up the sides, helping achieve different sounds. As for how it all comes together, Sherwood says, "Acoustically, the strings vibrate the bridge, which vibrates the front plate, which pushes air molecules inside the resonance chamber back to bounce off the back wall." He goes on:

When electricity passes through the coil a magnetic field is generated. Since I’m sending a square wave to the coil, the magnetic field is oscillating on and off at the frequency of the wave. I put a bolt through the hole of the bobbin, which becomes magnetized and vibrates with the magnetic field. The magnetic field from the bolt pulls and releases the string making it vibrate, which makes sound.

Coils1

An Arduino chip serves as the sculpture's brain; Sherwood says it "decides" what to play while continuously generating new music. The Arduino alternates between two modes; in one mode, it simply plays random strings. In the other, Sherwood says it will play patterns or sequences with certain strings and continue looping that same melody for a short period. More details are available at his blog, and you can see the Magnetophone in action below.