American Inroads WILLIAM WINANT / DAVID ROSENBOOM

PROGRAM NOTES It has been my intention for several years to compose a cycle of works for percussion and electronics which make use of the electronics as a tool for processing and transforming the percussionist's performance in a special way. This way involves not just the transforming of the percussion instruments' sounds on an acoustic level, but a processing based on information contained in the complex patternings manifested in the percussionist's performance. This could be likened to real-time algorithmic processing or algorithmic composition driven by the musical structure of what the percussionist plays.

This goal has been furthered by productive collaborations in an improvisationally developed music with percussionist, William Winant. This collaboration began in Toronto in 1976 in the context of work with various performing groups in concerts around North America and has continued since we both moved to the Bay Area in 1979. During these performances I have tried to use the electronics to create a single, jointly-played instrument which receives inputs from two or more performers, comprising not only sounds for direct processing, but also acoustic patterns which result in changing the operating characteristics of this instrument or even affecting a major restructuring of its stimulus-response characteristics. My goal was to further the artificial intelligence capabilities of such instruments and to create a more intimate linking of the performance activities among the members of a group.

The stimulus of these AMERICAN INROADS [in LA] concerts has resulted in initiating this cycle of works-in-progress titled, "Zones of Influence." It is a cycle conceived in five parts, the first tow of which have been prepared for their premiere on these concerts. The parts are:

1) "The Winding of a Spring" which is about evolution from disorder to order in rhythmic patterns through the spontaneous emergence of singularities that warp an otherwise uniform perceptual space into centers of gravity which attract and store more and more energy until full capacity is reached. There are two sub-sections, a) "The Stochastic Part" which evolved into b) "The Tripartite Structure," the most ordered part consisting of an hierarchical arrangement of patterns in threes or powers of three.

2) "Closed Attracting Trajectories" which explores a perceptual threshold occurring when one thing, (in this case a melodic shape), is transformed (bent) into another. This threshold is analogous to the catastrophic changes of state observed in natural phenomena when one aspect of a phenomenon is gradually varied, like water turning suddenly to ice when its temperature is gradually and continuously lowered.

In this work, a theory of perception which treats melodies strictly as contours or shape morphologies is used to affect two sets of melodic transformations between two precomposed melodies, known as the "Origin" melody and "Target" melody. Each set consists of 21 successive melodies beginning with the "Origin" and ending with the "Target." Each set describes a trajectory in a concept space mapping the similarity of each melodic mutation to the "Origin" and to the "Target." The first set presents the smoothest trajectory from "Origin" to "Target" and the second presents nine simultaneous trajectories ranging from relatively smooth to relatively disjunct, the latter realized through stochastic procedures.

The primary compositional controls involve manipulating the point in an evolutionary process where one thing loses its identity and becomes something else, and aspects of speed and rates of change of movement along these trajectories.

Still to come are three remaining pieces in this cycle: 3)"Given the Senses the Real Pregeometry" which is about the universe learning to perceive its own existence. 4) "Epigenesis, Ontogenesis, Phylogenesis, Parthogenesis" which is about ideas of evolution on genetic, individual, and group levels and notions about self-replication. 5) "The Buckling of a Spring" which is about the sudden release of energy through the dynamics of chaos.

The title, "Zones of Influence," reflects inspiration from and continued interest in writings by the great French thinker/mathematician, Rene Thom, author of the book, Structural Stability and Morphogenesis. A theory known as "catastrophe theory" is outlined in this book. It is an important new way of thinking about form and change.

Two ideas from Thom may be worth repeating here. First, "the characteristic of all form, all morphogenesis is to display itself through discontinuities in the environment." Second, the global macroscopic appearance of form results from the accumulation of local accidents, catastrophes of change. "Zones of Influence" refers to the region of space in which a structure of change known as a "chreod" can have an effect, much like the light cone in relativity.

David Rosenboom February 24, 1984 Piedmont, California

Typed by Cheryl Vega 8-30-95