_N_Polytope: Behaviors in Light and Sound after Iannis Xenakis_ is a spectacular light and sound performance installation combining LED lighting, lasers, sound, wireless sensors and machine-learning software, inspired by composer Iannis Xenakis’ radical 1960s-1970s works called _Polytopes_ (from the Greek _poly_, many and _topos_, space). _N_Polytope_ both re-imagines Xenakis’ research into probabilistic/stochastic systems with new techniques and explores how these techniques also exemplify our own historical moment of extreme instability. The work runs both as a 15-minute performance and in a continuously evolving installation mode.

The system interacts with itself, steered through a custom-developed wireless sensor network with software-utilizing machine-learning techniques, specifically from the research area of reinforcement learning in which software learning agents interact with their environment in order to achieve a goal. Physically, 150 ten-watt LEDs and 50 tiny speakers are suspended on 24, 20+ m stretched aircraft cables, which form a ruled surface. While the behavior of the LEDs creates a changing space of bursting points, the colored lasers that bounce off the surface of fixed and changing mirrors generate fleeting architectures of lines and shapes. Counterpointing the visual scenography, multichannel audio from the small speakers as well as the larger environment shifts between sparse natural and dense electronic textures. Across the architectural cable structure, the network of tiny speakers produces the behavior of mass sonic structures made up of many small elements (sonic grains) creating swarms of tiny sounds that resemble a field of cicadas or masses of insects—akin to Xenakis’ interest in the stochastic movement of mass structures. Thus the overall course of _N_Polytope_ is that of an event that is partially scripted and partially indeterminate, thus enabling the performance to continually move between order and disorder, tranquility and chaos.

Links: http://chrissalter.com/

Chris Salter (US/CA) is an artist, the Director of Hexagram-Concordia Centre for Research-Creation in Media Arts and Technology and the Associate Professor for Design and Computation Arts. Salter studied economics and philosophy at Emory University and received his PhD in the area of theater, with a second concentration from Stanford University in computer-generated sound. After collaborating with Peter Sellars and William Forsythe / Ballett Frankfurt, he co-founded and directed the art and research organization Sponge (1997–2003). His solo and collaborative work has been seen at major international exhibitions and festivals in over a dozen countries. He is the author of _Entangled: Technology and the Transformation of Performance_ (MIT Press, 2010).