Transfigurations: A Symphonic Work for Orchestra and Live Computer Processing

Abstract

Transfigurations is a symphonic work in one movement for orchestra and live computer processing utilizing the graphical audio programming language Pure Data. The score and patch for this piece are accompanied by an essay describing the audio processing techniques and the compositional processes employed in this work. Programming methods discussed include strategies for data capture, patch structure, user interface, and processor management. All audio processing in the work is realized in realtime. These sounds are derived directly from the orchestra in performance, except for the last. The processes involved in Transfigurations include pitch and amplitude tracking, pitch-shifting, filtering, frequency and amplitude modulation, granular synthesis, delay, and convolution. The final sounds from the computer employ stochastic processes for synthesis which are derived from the germinal materials of the piece. The essay also discusses the aesthetic philosophy and formal structure of the work, principle themes and motives, and formative pitch materials, as well as the compositional processes in each section. The final discourse of the essay considers microphone and loudspeaker setups, patch preparation and leveling, and strategies for rehearsal and performance.