Carthasis
Computer music concert of symphonic magnitude

'Günther Rabl Günther Rabl

A recording of a waterfall forms the basis of the full-length composition; however, more importantly than its function as acoustic material, it serves as an inexhaustible reservoir of forms and processes which can be derived from it by means of various analytical methods.

This recording is complemented by a number of "imaginary acoustic objects" – numerical oscillators (so-called physical models) designed especially for this purpose which are brought to life by the actual sound of the water and its transformations (often merely tiny excerpts).

In principle, this music is oriented to space: It was conceived for performance in a real space. All parts utilize 8 independent sound tracks, which can be assigned to other groups of loudspeakers in any section of the spatial production.

Level 1: "KATHARSIS" 13 min.
Level 2: "FUNKENFLUG" 19 min.
Level 3: "WIND" (in preparation) 6 min.
Level 4 (the last): "GROSSE FUGE" (in preparation) 30 min.

For years, I have worked again and again with a single piece of material: the recording of a thundering waterfall in the mountains of the Salzburg province. The four pieces named "Toccata" from "FAREWELL TEMPERED PIANO" were composed on that basis, as well as "Aufstieg" ("Ascent") and "Abstieg" ("Descent") in "ODYSSEE" ("ODYSSEY") and many others, both in the area of sound and in that of forms and processes. In "KATHARSIS", this roar is the only external acoustic material, the "raw material" from which almost everything is produced: sounds, sound processes, melodies, rhythms, spatial distributions, etc.

With Dynamic oscillators, one can define acoustic objects in the medium, the acoustic world of which is completely available, so-called "imaginary objects". They are silent at first, offering only a certain continuum of possible vibrations. The type of initiation is what determines the actual result.

The most obvious example is "FUNKENFLUG", the second part of "KATHARSIS". In this section, I defined nine objects (according to the model of a prepared string), and each of them were recorded carefully with regard to size, tension, elasticity, sustaining qualities, and much more, thereby creating an ambience of harmonized "objects" which can be immediately recognized as such. They are sounded in many different ways by the "sparks", since these sparks have various forms; they can be light or heavy, fast or slow. They can strike different spots; they can strike the object when it is at rest or while it is vibrating from the previous stroke. An imaginary acoustic object is created before our spiritual eyes.

Composition: 1991–94;
Duration: approx. 70 min.
Sound projection: over 8, 20 or more independent channels