Tetractys (1997) by Angelo Bello

For GENDYN Samples and UPIC System

This work was composed and executed at Les Ateliers UPIC in Alfortville (Paris) France, in 1997.

Form an equilateral triangle with yourself and a pair of loudspeakers as the vertices. Diffuse this piece through the loudspeakers and maintain your position for the duration of the work.

This work was composed with the 1991 edition of the UPIC System developed by the engineers of the CEMAMu. It was a technical evolutionary step forward of Iannis Xenakis’ original invention that used an electronic drafting table connected to a computer and bank of oscillators. The 1991 edition also utilized a bank of 64 digital oscillators and permitted, with very fine granularity, the drawing and specification of so-called arcs in an ambitus that ranged from a fraction of a hertz to 20kHz. For this piece, samples of the GENDYN algorithm were imported into the UPIC system (the samples were generated with The New GENDYN Program - developed by Peter Hoffmann - which in 1997, was newly born).

All spatialization and movement of sound that is experienced by the listener is achieved as an emergent by-product of the process of synthesizing the sound itself. The algorithm that I created with the UPIC system incorporated the feedback frequency modulation feature of the system, enabling bursts of chaotic tones and structures to emerge. No L/R balance controls or external processing was applied to the sound signal - all movement and timbre generation is an outgrowth of the algorithmic action applied to the bank of digital oscillators as their resulting data intermingle with the physical architecture of the system itself.