Having recently acquired a semi modular synthesiser with two Voltage Controlled Oscillators (VCO’s), I wondered whether the voltages from electrochemical reactions might modulate the pitch of the oscillators, hopefully in an interesting manner..

Two voltages from the reactions between copper, aluminium and iron in a solution of NH3Cl patched to the VCO inputs altered the pitch of the two oscillators.

However only movement of the apparatus produced audible pitch changes. Left alone the pitch changed extremely slowly as the reactions progressed, not producing sufficient rapid voltage modulations to produce perceptible changes of tone.

Perhaps carbon probes in closer proximity or a matrix of probes and a more active electrolyte might produce varying voltages that would change in seconds rather than over many hours. These might then dynamically modulate the oscillators and produce interesting and perceptible changes of timbre.

Evolving crystalline formation.