Page  35 ï~~AUDIO GAME INTERACTIVE PERFORMANCE Silvia Matheus Tom Keller CNMAT SOUND CONCEPTS 1750 Arch Street P.O. Box 104348. Berkeley, CA 94709 Oakland, CA 94610 AUDIO GAME: Installation and Performance Composer: Hans J. Koellreutter; Co-composer & Project Coordinator: Silvia Matheus Engineer. Tom Keller Demonstration of the performance interface and algorithms for an orchestral piece called AUDIO GAME, written in 1992/1993 by Hans Koellreutter and adapted by the presenters for computer and active listener. An explanation will be part of the presentation of the piece. It will be spoken in four different languages and will be played back through the speakers during performance of the piece. The idea of this presentation is to have the performer, i.e. the spectator, be a full participant in the execution of a pre-arranged work. The goal is to understand the philosophical and musical implication of the composer's work, and enter into dialogue with the art by manipulating musical ideas through the interaction with the sounds. Intimacy with the art becomes possible through close contact between the audience and the piece. The movements of the listener/performer activate processes which are translated to standard digital code (MIDI) and interpreted by a personal computer which sends the signal to synthesizers, then to a signal processing box, and finally to several speakers. The performer will have access to different types of controls to manipulate the sounds; and so be able to influence parameters including speed, amplitude, velocity, filtering and transposition, combining with the composer's style. The graphic representation of the piece on the computer screen is an animation of the original score. There are three diagrams representing three structural movements. The diagram represents in a graphical form the compositional rules which affect the piece. It does not represent a fixed score; rather, simple geometric figures and the relations between them indicate the algorithms which structure the game which the performer plays to create the piece. The presenters of this demonstration have made an electronic version of this piece, following the structural rules determined by the original diagrams. The program includes an implementation of the rules encoded in the diagram, and an interface to be used for the performance of this work. As part of the demonstration, listeners will be invited to perform/control the piece themselves. The listener enters into a small dark room which has a computer with a big monitor screen showing an (animated) graphic diagram of the work Audio Game, a hidden Buchla Lightning (or similar gesture sensor) in the back, and speakers. Explanation about the performance and the composer' s words will be posted on the wall as the listener enters the room. The listener hears a spoken voice through the speakers which is the composer's aesthetic view of his work. As the listener gets closer to the computer, the Audio Game piece increases in volume and the talk becomes the background of the piece. He or she will listen to the talk together with the piece, and during the performance, visual clues are shown on the computer screen to prompt interaction with the piece. It is a game in which the listener has to listen and interact; the time of interaction varies, determined by the laws created by the composer as part of the piece. The piece will be always activated with a spectator presence in the room. ICMC PROCEEDINGS 1995 35 35

Page  36 ï~~In the words of Hans Koellreutter: "The style of Audio Game is structuralist, planimetric and dynamic in that there are not defined components, fixed, stable and precise. It is possible to say that the planimetric structure of the piece is in nature aleatory, since the structural units substitute the melody, harmony and other characteristics of traditional music, creating an idea of a web of inter-relations in constant movement... "It is a game in a variable form, mobile and schematic. It is a game between sounds and silences, audible and no audible sounds, real and virtual with no compositional ending. The composition has no, beginning or ending between the components of the score and the music appreciators. "Audio Game is open-ended, which implies a full participation of a listener or a performer, who becomes the co-author of this composition. The inter-relation between the components of this score are mediated between sonorous fields obeying the variation principles of transformation, change of sounds and duration of values or any other type of relationship..." 36 I C M C PROCEEDINGS 1995