An investigation of audio signal-driven sound synthesis with a focus on its use for bowed stringed synthesisers

This thesis proposes an alternative approach to sound synthesis. It seeks to offer traditional string players a synthesiser which will allow them to make use of their existing skills in performance. A theoretical apparatus reflecting on the constraints of formalisation is developed and used to shed light on construction-related shortcomings in the instrumental developments of related research. Historical aspects and methods of sound synthesis, and the act of musical performance, are addressed with the aim of drawing conclusions for the construction of algorithms and interfaces. The alternative approach creates an openness and responsiveness in the synthesis instrument by using implicit playing parameters without the necessity to define, specify or measure all of them. In order to investigate this approach, several synthesis algorithms are developed, sounds are designed and a selection of them empirically compared to conventionally synthesised sounds. The algorithms are used in collaborative projects with other musicians in order to examine their practical musical value. The results provide evidence that implementations using the approach presented can offer musically significant differences as compared to similarly complex conventional implementations, and that - depending on the disposition of the musician - they can form a valuable contribution to the sound repertoire of performers and composers