Furthering my previous interests in Stochastic Synthesis I implemented an emulation of Iannis Xenakis’ Dynamic Stochastic Synthesis on an Arduino micro controller, the resulting algorithm I titled GenDynish.

An interactive version of this work, titled A.001.i, was developed for performance at Oscillo Scape 11 in September 2018. It involved three rotary/push controls that adjusted parameters of the algorithm in real-time and allowed manual setting changes during performance. This used extended hardware developed for the first composition (A.001) that employed a Teensy LC micro controller. Another extension was the additional animated Neopixel light strip that reinforced the internal algorithmic changes by changing light state coincident with them.

Photo: TBC

A version of the GenDynish algorithm was re-written for the Circuit Playground Express micro controller in June 2018 and used as part of a live-algorithm performance with colleagues in the Sawdust Collector concert series at the Gold Saucer Studio in Vancouver, Canada, on 17 June 2018. This version included some live control via MIDI from a Pure Data patch.

Above: The Playground Express version of the GenDynish algorithm under development in Canada.

The first composition using this code was the work A.001, which was quadraphonic real-time rendering, performed at the Music Technology Welcome Concert in March 2018 at the Queensland Conservatorium Griffith University in Brisbane, Australia. A recording of this work is linked to below.

In the 1990s Iannis Xenakis developed a new probabilistic audio generation method called Dynamic Stochastic Synthesis that produced quite unconventional sounds. This process reflected his interest in “human intelligibility [of] temporal periodicity and the symmetry of the [waveform] curves” generated by digital devices (Xenakis 1992:289). Two notable works using this technique were composed by Xenakis, Gendy3 and S.709. Inspired by these works and taking advantage of the rapid advances in technology, “A.001” simulates this technique on the low cost Arduino microcontroller running in real time and emulates the four voice architecture of Gendy3 only this time reproduced in quadraphonic sound.

I had previously engaged with dynamic stochastic synthesis in 2004 coding the first real time, interactive, implementation of the process. The resulting IDSS system was performed and published in computer music conferences in 2005. This implementation on the Arduino sounds similar, but is technically ‘in the spirit’ of the process rather than a literal reconstruction as was IDSS. It is also testament to the advancement of computing hardware that synthesis processes once requiring expensive and time consuming resources are now achievable on the least expensive of systems.

The early prototypes were designed to check the capability of doing this at all via the PWM pins on the Arduino. These prototypes extended earlier explorations of simple Arduino audio for handmade electronic instruments. A four channel version of GenDynish was designed for performance and the A.001 composition was presented using a quadraphonic sound system.


For CPU performance reasons the concert version was migrated to a Teensy micro controller. A simple housing made it almost road worthy, as shown below.

This work continues my long-held interest in algorithmic music systems, and the reliance on probabilistic automated processes connects to my more recent contemplations about material agency in computational systems and the resulting co-creative processes. Happily, the sonic results are quite rich and the sound world impressively vast given the simple processes from which these emerge.

Xenakis, Iannis. 1992. Formalized Music: Thought and Mathematics in Music. Stuyvesant NY: Pendragon Press.
GenDynish – Xenakis on the Arduino