A Performer-Controlled Live Sound-Processing System: New Developments and Implementations of the Expanded Instrument System

The Expanded Instrument System (EIS) is a performer-controlled delay-based network of digital sound-processing devices designed to be an improvising environment for acoustic musicians. The EIS emerged from Pauline Oliveros’s work dating back to the 1950s. In the last 5 years David Gamper has been developing and expanding the capabilities of the EIS; he describes in this article how performance experience has led to recent technical developments and relates how the current configuration of the EIS has been used in composition, performance and teaching activities. He also discusses why seemingly outdated analog technologies have been retained in the EIS after adaptation to allow computer control. The core concept of the current configuration has proved to be flexible and adaptable to many demands, several of which are described.