Self-Organised Sounds with a Tremolo Oscillator

Risto Holopainen
DAFx-2010 - Graz
Tremolo is usually regarded as belonging to the domain of note embellishments. Rapid tremolo, taken into the audio range, is an interesting synthesis technique which is related to FM and granular synthesis. We present a tremolo oscillator, capable of a wide range of sonorities, and illustrate some of its capabilities in applications such as feature-based synthesis and sonification. A reference implementation in Csound is given. The tremolo oscillator is then put into a feedback system, where its output is subject to feature extraction, and the extracted features in turn are mapped to its control parameters. Chaotic orbits in this feedback system guarantee continuous variation, in contrast to the trivial periodic patterns that are easily obtained.