Per Holmquist has always had a finely tuned ear for music. "When I hear a song for the first time I know, 'Okay it will be a hit,'" he says. But he never learned to play an instrument. Taking lessons and learning how to read sheet music for a new instrument would be too hefty a commitment, so for his graduation project at Beckmans College of Design in Sweden, the student designer (and disc jockey neophyte) built a foolproof digital percussion machine.

Beat Blox, as it's called, is a beats-making station Holmquist built with rudimentary turntables from a local Stockholm DJ shop, Arduino boards, sensors, and some very simple building blocks. The entire system comprises three separate turntable stations, each one with their own specially programmed Arduino board hidden underneath. Each Arduino mimics a different instrument: One plays the bongos, another plays the bass (Holmquist tapped the standard Music Instrument Shield for those), and the third plays the snare drum, which Holmquist specially programmed after finding a discarded drum set.

To use it, players just put little wooden blocks on the turntable platter. Distance sensors cling to the underside of the turntable arm; as players add blocks to the spinning platter, the sensors read the varying distances and the Arduinos will emit different percussive loops of sound. It’s like training wheels, for beat-boxers.

Because each of the three turntables spin at the same speed, Holmquist says the beats almost always work well together. That harmony helps facilitate the desired intent of Beat Blox: At the annual graduation shows, “it’s hard to get exactly what the students are doing. The projects and visitors have been introverted. I wanted this to be a two-way communication,” he says. The simplicity of the design—each turntable only has five sensors, only plays tones from one kind of instrument, and gets visualized with the blocks—makes it just as playable for the musically inclined as the musically stunted. “Some visitors are musicians, so they know where to put the blocks for the snare, or the bass, and some people are graphic designers, so they just make nice patterns.”