Already for a time I have been planning to combine algorithms that I have been using
in two different groups of works:
In the sequence Lokale Orbits, which started with pieces for solo instrument and tape, recordings with musicians concerned were the starting point of compositional process. The variety of possibilities of processing sounds with granular synthesis lead me to the decision to begin experimenting with synthesis parameters and then follow the results, often against the original compositional intention. Nevertheless within the progress of the sequence some common structural elements emerged: reduced material, the combinatorial reordering of a few instrumental gestures and slow algorithmically controlled changes in the tape part.
In older pieces for acoustic instruments computer experiments were the starting point too, but here in connection with polyphonic coordination respectively the control of traditional parameters of instrumental thinking.
Although the sounding results were very different I used similar algorithms in both cases with the aim of establishing correlations and variation, often combinations of cycles and random.
Hybride Strukturen 1 also starts from the solo instrument, the bass trombone, and some granular processings. The string quartet is only playing in sections. Its algorithmic control follows a pulsation that corresponds to the carrying layers, continuous granular textures and gestures of the solo instrument.
The work was composed as part of a project about algorithmic composition lead by Gerhard Nierhaus (IEM Graz) and was supported by GesFEMA.