Computer assisted application of stochastic structuring techniques in musical composition and control of digital sound synthesis systems
Although many sophisticated computer sound synthesis systems have recently been developed, their use remains significantly under-exploited by composers. This is due to a large extent to the cumbersome and detailed programming invariably necessary in order to produce even the simplest of sounds. So, for effective and efficient useof computer sound synthesis techniques in musical composition, certain generative methods of forming and controlling data structures can be a powerful aid. This thesis proposes and develops such methods. Techniques of pattern formation are described which have been developed and used in the original compositions of the author. These are based on stochastic generative schemes. The examples cited develop across the spectrum of complexity, ranging from the application of simple probability distributions through to intricate structures of interrelated stochastic constraints under the control of a general grammatical schema. In some cases the computer output has been designed so that it can be transcribed for performance by conventional musical forces. In other cases the output data has been used for direct control of digital sound synthesis programs and equipment. In addition to the limited practical resources existent at the City University, the author has been able to work with facilities made available on practical research visits to other institutions in Europe. The structuring techniques employed by the author are compared with other research taking place elsewhere, and are set in the context of recent advances in the development of certain formal grammars for the description of musical structures. Methods of general application of the techniques are suggested, and in particular, in the light of the development of alternative methods of non-standard synthesis, the use of stochastic web grammars is proposed not only for the macro-structuring of notes or sound objects, but also in the definition of sound complexes and timbres. The techniques explored have an explicit use as a practical tool for composers and may be incorporated into, of form the basis of, computer controlled compositional aids of wide ranging application.