Abstract: A system for synthesising sounds which allows the user to specify time varying functions for multiple partials. The partials can be cyclical waveforms, for example sine waves, or sampled sounds, or a mixture of each. Partials can be included in the resulting sound by summing, convolution or otherwise. Time varying functions can be specified for the amplitude, frequency or other characteristic of each partial. In some embodiments the resulting waveform can be displayed in various formats to assist with visualising the result of the synthesis.