Quartet is a musical instrument that creates music from the city of Amsterdam. It uses the four inner canals as strings, and the bridges over those canals as frets. Each time a cyclist crosses a canal, they trigger a sensor which sends a wireless signal to the instrument, which plays the corresponding note. The music of the city has always been there, now there is a way of hearing it.

Quartet creates a way to hear the combined sounds of the city in real time, an ambient symphony that runs 24 hours a day.

Quartet was designed to use the four inner canals, but could also be adapted to use any data, with any number of different triggers. The audio stream could also be broadcast online and even sampled for use in live performances if so desired. Quartet consists of a sound box (30 x 20 x 10 cm) with four strings. Each string is plucked by a continuous rotation servo, mounted with a drive shaft and toothed rotation wheel. These four servos are powered by an Particle Electron microcontroller that receives signals over a 3G wireless network. The sensor boxes are 10 x 10 x 5 cm and contain another Particle Electron, connected to a 90 x 3cm band of pressure sensitive material.