music of the mycelium
l-systems
Lindenmayer systems (L-systems) were described In 1968 by Aristid Lindenmayer, a biologist who worked with yeast and filamentous fungi. These were string rewriting systems, which could be used for defining objects by successively replacing parts of a simple initial string (axiom) using a set of rewriting rules (productions). These strings are commonly interpreted using Turtle Graphics so that a simple axiom and production rules could code for a visual representation of a relatively complex plant, alga or filamentous microbe.
microbes and music
We have developed win software (lsys2midi) that interprets L-system strings sonically (Turtle Sonics?), producing a MIDI file as output. We applied L-systems representing fractals, bushes and filamentous microbes. The work is described in a paper "Microbes and Music" presented at the PRICAI2000 Artificial Intelligence Conference in Melbourne in August 2000. A special web site has been set up to provide more information (see below for web and paper details). The resulting MIDI files were used to produce music using conventional and specially prepared sounds on a Yamaha CS1X synthesiser. Fran wrote the L-systems as parametric L-systems, the sounds were put together by Jacques.
fractal (2000) 3:51 mp3
Self-similarity is a feature of true fractals like the Koch curve, and the musical output can be repetitious. This piece is based on an L-system describing a Koch curve. To give some sort of feeling of movement to the repetition, the MIDI file was recorded using 8 different sounds (performances) on the CS1X. Loops of these were mixed together using Acid Music. The resulting mix was then digitally treated 3 times and mixed again for the final piece.
twin bush (2000) 5:11 mp3
In Prusinkiewicz and Lindenmayer's wonderful book The Algorithmic Beauty of Plants, there were a number of L-systems presented for bushes. These were rewritten as parametric L-systems and the MIDI file for one of these (pictured) was played with a newly created CS1X performance called ra14. This piece is an Acid Music mix of five loops taken from the resulting music.
mycobeat (2000) 5:51 mp3
The MIDI file produced by a theoretical microbe growing with dichotomous branching was played using a number of presets on the CS1X. This was augmented by beats from a Yamaha qy70 (a simple preset, not produced by an L-system). No extra processing was used here.
mucorales (2000) 4:23 mp3
The MIDI file used in this piece was generated from an L-system written to represent the growth of the fungus Mucor strain M41. This L-system was modelled on real-time data collected for the growth of this fungus. The MIDI file was played using the ra15 "performance" created on the cs1x. Initially two digitally treated versions of this output were mixed together and represent the first part of the composition. In the second part, the untreated output is used.
