Published in the SDF Music Compilation CD Volume III
Ex-tream is part of a specific musical project that seeks to combine sound synthesis with ecology, called eco-structuralism. The project investigates new methods for musical composition derived from analysis into the behaviour of environmental sounds, or sounds of the natural environment.
Ex-tream was composed entirely using a 20 second audio sample of a small stream flowing at a moderate rate through slightly rocky terrain. The sample underwent a number of processes, and layering which transformed it into a musical composition, quite different yet still somewhat reminiscent of the original.
Using the jMusic library (GNU GPL), I created the audio tools used for analysis and composition.
To begin with the sample was incrementally stretched until it began to quantise. With this highly magnified sample (in this case up to 71X magnification) the individual frequencies and timbre that make up the original sample can be easily heard, dissected, analysed and used in composition. The stretching process is achieved one cycle at a time, so that it can be done in a single stream without phasing problems. This is how the sample is able to stretch so much without a major loss in clarity, other than the quantisation effect, which in this case was a desirable element.
The quantisation can be overcome with a simple interpolation algorithm, but the chatter effect is sonically very interesting. This chatter effect was multiplied with layers all stretched to vary degrees, some quite similar which causes a few interesting phasing effects. The sustained notes were derived by an abstraction method which measured the amplitude of the peak of the sample and transformed the consecutive peak amplitude values into frequency values, which were notated and performed on a small pipe organ.
For more information on the process, for audio tools, or other music, go to my website: http://www.ecostructuralism.com
