1998 26:30 8
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Although on the level of sound synthesis and structure there is hardly any relationship between the earlier analog Depths of Field pieces and Torso, there is one common aspect: All the sound material was organised into a family tree that shows how every material group is derived directly or indirectly from a source material by means of transformation processes.

Since in the Depths of Field pieces this source was an aleatoric structure, little had to be composed after all the material groups were produced; neighboring relationships were guaranteed by the source material's structure and the transformation processes' 'transparency' for this structure. The large form consequently emerged from the sound material by placing transformation results in a specific order.

In Torso, however, the source material consisted of a recorded set of separate violin sounds. A very sensitive contact microphone was placed at the bridge of the instrument after which a rich variety of relatively abstract sound materials could be produced by just touching the body (its 'torso') in different ways. A continuous recording of approx. 15 minutes was later spliced into 19 segments, which again were sub-divided into a, b, c,…
The separate sounds were then all transformed one by one by means of various transformation processes, resulting in new material groups with an equal amount of separate sounds.

violin used for the source material family tree for sound production score page from part 1 score page from part 2

For the sound transformations I used a program written by Digidesign called "Turbosynth". This program recalculates samples in RAM on the basis of graphically patched modules that consist of a certain audio function such as ring-modulation, filtering, enveloping, transposition, time stretching/compression, spectral inversion, etc.

Despite their complex micro structure, the resulting sounds show no musical development in themselves; every single sound or sound transformation represents a more or less static 'field'. In order to create a large form that was musically meaningful, I felt that an additional structural principle had to be superimposed onto the material after all the sound transformations had been executed. For this purpose Gottfried Michael Koenig's computer composition program Projekt 1 was used.

Inside this program the parameters of a musical structure are calculated on the bases of a number of processes that can vary from very irregular (1) resulting in series without repetition of list values, to very regular (7) allowing a certain maximum of value repetitions. After all the input data has been entered (which includes addressing a separate process number to every parameter for every section), the computer calculates an output structure that can be read on the screen or printed in the form of a list.

The output of Projekt 1 was interpreted as follows:

PR 1 score file
entry point
entry point (multiplied 10 X)
sound number (within a group)
material group number (within the family tree)
instrument number
sound layer (within the final structure)

Sounds that have a clear pitch were generated according to the pitch indication from the score file in parts two and four.
In the multi-track version of Torso, the instrument number also indicated the spatial position of the sounds.

Torso was commissioned by the Fonds voor de Scheppende Toonkunst.