The Bohlen-Pierce Symposium
First symposium on the Bohlen-Pierce scale, Boston, March 7 – 9, 2010
Wessel: Designing and Performing Spectra Compatible with the Bohlen-Pierce Scale
Designing and Performing Spectra Compatible with the Bohlen-Pierce Scale

David Wessel
Center for New Music and Audio Technologies (CNMAT)
Department of Music University of California Berkeley

Two real-time additive approaches to the synthesis of materials in the Bohlen-Pierce scale are presented.  The first uses hundreds of  sinusoidal components and the second exploits a large bank of high-Q resonate filters.    In each case spectral profiles are defined on a 96000 cent grid.The sinusoidal component synthesis control method involves migrating individual components from one spectral profile to another providing for slowly evolving and perceptually seamless  spectral evolution.   For timbres with percussive or plucked-like attack transients the resonate filter bank is used.  The performance control interface consists of an array of two dimensional pressure sensitive pads interfaced by Ethernet to a computer running Max/MSP.  Each pad has a number of  spectral profiles mapped to it in such a way that movements of the fingers control transitions.  Pressure is used to control dynamics.  The layout of the profiles on the performance interface was designed in an iterative manner to facilitate discovery through exploration and improvisatory performance.