Complexity Study I and II
Summary
Two compositional studies based on the idea of complexity, explored in two radically different ways. First, as a feedback network of frequency-modulating oscillators, then as an exploration of periodic and aperiodic trajectories in self-referenceing lookup tables.
Supported by
The composition and design of the special software for these compositions took place within the research project Creative Performance, funded by the Swedish Research Council.
Description of project
Two compositional studies based on the idea of complexity, explored in two radically different ways. First, as a feedback network of frequency-modulating oscillators, then as an exploration of periodic and aperiodic trajectories in self-referenceing lookup tables, interpreted as rhythmic and melodic source material.
In Complexity Study 1, the idea of low-dimentional deterministic chaos in oscillator feedback networks comes from Dahlstedt, Nordahl and Linde's work investigating the general mathematical properties of such networks in large-scale simulations in 2003 and 2004, as described in Dahlstedt's doctoral thesis Sounds Unheard of, Chalmers University of Technology, 2004. It was there shown that the chaotic behavior depended in a specific way on the strength of the feedback connections and the number of feedback connections. In the current study, this is illustrated in a simplified model, where a network of eight oscillators are randomly assigned pitches within a given range, and then a randomized matrix of connection strengths is slowly and gradually faded in. The audible result is a transition from a cluster of sine waves to a strictly chaotic complex timbre, and back. Along the way, the system passes various ordered regions, and with periodic and quasi-periodic behavior. The process is repeated four times. The eight oscillators are panned from left to right, giving the impression that the listener are seated inside of this very strange sonic system. There is also a four-channel surround version of the work.
In Complexity Study 2, the idea of exploring periodic and aperiodic behavior of self-referencing lookup tables comes was inspired by the research of Stuart Kauffman on the behavior of Boolean networks, as described in his seminal book The Origin of Order (Oxford University Press, 1993). In such a system, the tracetory is bound to end up in periodic or stationary behavior, but when perturbed, the trajectory can suddenly shift and end up in a completely different behavior. The most interesting behavior is when the system is repeatedly perturbed, which is her achieved through the gradual cross-fading between two sets of lookup-tables. As the tables change, the sequences change in a very interesting way. There are four parallel such systems going on at the same time, controlling different parts of the electronic music. The state changes of the systems are mapped to pitch, dynamics and some timberal parameters in a musical texture generated in real time. The composer may interact during the performance, for example by re-randomizing one or more of the lookup tables.
Both pieces are implemented as live generative algorithms running on a Nord Modular G2 signal processing platform, with some interaction by the composer. Since they are generated in real time from complex systems, they sound different each time, and the submitted versions are just example instances of the works.
Type of work
Konsert - del av projekt; World premiere of two compositions for live electronics solo, performed at the curated live part of the FARM Workshop of Functional Art, Music, Modeling and Design, a part of the 19th ACM SIGPLAN International Conference on Functional Programming
Published in
Live performance at 3:e våningen, Sockerbruket 9, Göteborg, Sweden
Link to web site
https://soundcloud.com/palle-dahlstedt/complexity-study-i-oscillator-networks
https://soundcloud.com/palle-dahlstedt/complexity-study-ii-periodicity-in-recursive-look-up-tables
http://functional-art.org/2014/
Date
2014-09Creator
Dahlstedt, Palle
Keywords
Complexity
Complex systems
Electronic music
Generative music
Algorithmic music
Publication type
artistic work