The Electronic Music Studio of the W.D.R.

Sound manipulations for a new musical expression were made possible by the advent of the magnetic tape. Different sorts of discs and rolls previously used to store sound recordings were not malleable for such creative purposes.

The concepts and the names of ``sound objects''^1.3and Musique Concrète, both created by Pierre Schaeffer and Pierre Henry in Paris at 1948, were given to pre-recorded samples of natural sounds, Objets Sonores and to their use for music composition, Musique Concrète.

However the creation of a true synthetic music took place in Cologne, at 1950 in the entourage of Herbert Heimer.

The main approach was different from the Musique Concrète. In this synthetic music electronically generated oscillations were first recorded on fragments of magnetic tape which were then manipulated in any possible way. Mixing and changing the playback speed were the most often performed manipulations.

In 1957, Ligeti was assisting Gottfried Michael Koenig in the electronic music studio of the Westdeutscher Rundfunk in Cologne for the realization of a piece called Essay.

Essay by Koenig was mainly composed of sinusoidal sounds which can be easily followed by the ear at some points but at other moments, those sounds formed interesting conglomerates where none of them could be individually spotted. That was due to the extreme brevity of them and to the high speed of their succession in time.

In Essay, the simultaneity of sounds above and below the differentiation level of the ear^1.4 created an interesting texture.

In this texture one could spot and follow those sounds above the perception threshold, sounds longer than 50ms., as a kind of ``melody''. At the same time, sounds below that threshold, shorter than 50ms., are perceived as if they were ``simultaneous'' with the others. Even when they were not. That ``false simultaneity'' not only created an interestingly complex sound aggregate, but another quality, previously unheard of, emerged as well.

Koenig called this quality the ``sound (timbre-color) of movement'' Bewegungsfarbe [1]. Rhythm is not anymore perceived as a motion but instead rather a constantly changing sound-color is heard.

More layers of this composite ``sound-color'' could be created by varying the dynamics of the component waves.

Seen from today, it seems that Koenig and Ligeti have ``discovered'' the principle of Granular Sound Synthesis^1.5.

In Granular Synthesis extremely brief sounds, when agglomerated create a layer of a complex timbre.

Each of the ``grains'' can be varied in pitch, intensity and overtone components^1.6 while the overall pitch and intensity of the whole complex can also be made continuously changing.

Today, Granular Synthesis is widely used tool. Various computer software exists and it has various implementations in the Csound electronic music software^1.7

In an article formerly published in a compilation named Rückblick in die Zukunft^1.8, republished in[1], Ligeti describes the basic method of working in the Cologne studio:

[...] a sinusoidal current generator creates sine-waves at a controlled frequency. Those waves are recorded, separately, on magnetic tape. Complex waves can be obtained by mixing those sine-waves. Following a pre-defined compositional plan, the tape is cut into pieces and re-assembled to form the desired succession of sinusoidal and complex sounds. Then those sounds are played simultaneously on two tape recorders and the mix is recorded on the third tape-deck. During the copying process the volumes of the sources can be freely altered. The resulting tape is then cut and the fragments are assembled again and mixed with others.

The process can be repeated ad infinitum but the building up of the background noise during the re-mixing process limits its practical use to two or three ``generations'' at the maximum.