This koji sonification turns koji's growth, heat, and enzyme activity into music and motion. It’s written on the Yo scale—a bright 5-note Japanese folk pentatonic. I sketched the melodies; Duncan Geere at Loud Numbers handled the sound design, sonification, mixing, and mastering.

Development

data

The data and phase definitions come from Nakaji Minami’s excellent beginner koji book, Koji for Life. To be precise, the phases overlap—e.g., during the germination phase the mycelium is already beginning to grow. Here, each phase is characterized by its dominant activity and separated for clarity. Another excellent resource is Controlled Mold, which also describes the process in three phases.

sound design

For the music, I first chose a scale—something that felt Japanese without leaning on stereotype. The Yo scale is pentatonic (five notes per octave) common in Japanese folk music. It has no semitones, which gives it a bright, open sound—and I wanted to convey a sense of playfulness. Drawing inspiration from ambient music, especially the band Lullatone, I sketched simple, repetitive melodies on the MIDI keyboard so the music could feel like it was growing and evolving, like the koji itself.

germination phase

mycelium phase

enzyme phase

Starting from my MIDI sketches, Duncan took my MIDI sketches and designed sounds that would evolve over time, using techniques like granular synthesis and layering to create rich, textured sounds. He took a lo-fi and sparse approach to sound design, inspired by experimental music and indie pop. It was created in Ableton using a mixture of field recordings that I took from my own koji making journeys, synths, and hand-made effects.

animation design

I drew the visuals in Procreate and kept the lines a bit “alive” to mirror organic growth and to make it seem tactile. The audio and timeline were further aligned in After Effects.

Curious? If your ears disagree or agree with my enzymes, I want to hear about it!

The Process of Making Koji