Will James
Music technology researcher in New York, NY
Music Enhancement Hardware Project
June 2025: Iola Walker
github.com/willbjames/iolawalker
In music, polyrhythms are propulsion-generating, overlaid figures prescribed according to principles of musical tension and release. For example, in a jazz song with swung 4/4 time, a piano player might play a polyrhythmic figure of dotted quarter notes to induce excitement underneath an improvised solo. This two against three polyrhythm is a common one: a hemiola.
The ‘iola’ walker system is a medium for composing music to be played while the listener is walking. Musicians record songs with a walking listener in mind, imagining typical walking paces while playing improvised parts. Multiple versions of the same song are recorded with a variety of underlying polyrhythmic pulses.
A listener goes for a walk, and the Iola Walker app detects their walking pace. Iola Walker picks up footfalls using a foot-mounted accelerometer, processing the signals in real time using a recurrent neural network in an android app. The android app outputs a midi event for each footfall. The iola walker player, which might be a VST running in a DAW, plays the version of the next music passage with underlying polyrhythms closest to the listener’s walking pace.
