For four computer- synthesized soundtracks

"Riverrun" creates a sound environment in which stasis and flux, solidity and movement coexist in a dynamic balance. The corresponding metaphor is that of a river, always moving yet seemingly permanent. The sound in this composition which bases itself on the smallest possible "unit" of sound in order to create larger textures and masses.

All sounds in this piece were real-time generated with synthesis by the DMX-100 Digital Signal Processor, up to a maximum density of 2375 grains/second. Most layers were multi-tracked with four simultaneous stereo versions and later mixed. Considerable use was made of ramps applied to the synthesis variables; that is, certain parameters were made to change over time at a specific rate, sometimes with several parameters simultaneously ramped at different rates.
"Riverrun" was commissioned by the Music Section of the Biennale di Venezia with the financial assistance of the Canada Council.

This work is entirely realized with the method of sound production known as granular synthesis. With this method small units or "grains" of sound are produced, usually with very high densities (100-2000 grains/sec.), with each grain having a separately defined frequency and duration. In the current implementation with the author's PODX system, there are two possible synthesis models, the first assigning a particular waveform to each grain, and the second defining a simple frequency modulation (FM) event. When the grains all have similar parameters, the result is a pitch and amplitude modulated sound, but when random variation is allowed in a parameter, a broad-band noise component is introduced.