François Rose: Expansion of Orchestration Technique Through the Use of a Spectrally Based Computerized Orchestration Aid

François Rose is a composer and associate professor at the Conservatory of Music, University of the Pacific, USA

ABSTRACT:
A computerized aid to orchestration that greatly extends the use of spectral analysis in orchestration is introduced. It is made of two parts: a bank of Fast Fourier Transforms (FFTs) accessed by a group of sub-routines designed to either perform sound analysis or propose different orchestrations that imitate the spectral energy pattern of a reference sound.

The tool's potential to perform quasi-instantaneous spectral analysis of sound mixtures is illustrated with a reference to Schoenberg's Five Pieces for Orchestra op.16, III. The method used to obtain these analyses is presented.

The tool's ability to propose sound mixtures that imitate a reference sound is demonstrated with two examples from the composer's work L'identité voilée for clarinet, violin, and piano, where the trio imitates the energy pattern of a clarinet multiphonic tone. A reference to Xenakis' Orient-Occident is made to illustrate the tool's potential in the context of electroacoustic music. The mathematical procedure used to obtain these orchestral matches is presented. It is shown to be a data matching technique based on an advanced method of spectral decomposition.
Finally, excerpts from the composer's La défaite d'Héra for saxophone quartet are presented to show the latest development of the tool.

http://www.pacific.edu/conservatory/faculty/frose.asp