Velosynth is a bicycle synthesizer, designed to form  “a cognitive loop between the cyclist and their microlocal transportation environment.”

You may not have realized that you were missing that “cognitive loop between the cyclist and their microlocal transportation environment.” But now you know.

A sensor detects the rotation of a spoke-attached magnet. this data is translated into sound via an arduino microcontroller, 8bit R2R DAC, lowpass filter and audio amplifier.

You can follow the development of the bike synth at Velosynth.com.