The unity of Xenakis's instrumental and electroacoustic music: The case for "Brownian movements".

TECHNOLOGY AND THE AUTONOMY OF COMPOSITIONAL PRACTICE

XENAKIS'S INSTRUMENTAL MUSIC (including also vocal music) has already been studied in many articles, reviews and even books. (1) However, there are still only a few analyses of his electroacoustic music, (2) and we have only general commentaries about the relationships between his instrumental and his electroacoustic music. The present paper is an appeal for further analysis in this third area. In an attempt to show the unity of Xenakis's instrumental and electroacoustic music, I will focus on one particular topic: the influence of Xenakis's experience with random walks used for sound synthesis in the late 1960s on his instrumental pieces of the 1970s.

This topic has to be connected with the general question: what is the influence of music technology on music? It has often been said that the composers of the 1950s were much influenced by their electroacoustic experience, transposing their results in this domain to their instrumental music. David Ewen wrote that Xenakis, in his early work, "explored the possibilities of simulating electronically produced sounds and sonorities with conventional instruments." (3) Hugues Dufourt made the same statement, probably thinking about his own music and "spectral music." (4) However, this is not precisely true. It is true that the electroacoustic practice of the 1950s made Ligeti, Stockhausen, and Berio discover radical new ways of conceiving music in general, and that they applied these new ways of thinking to their instrumental music. But Xenakis is more like Varese, who wrote radically new music before the introduction of the new technology, a music that is no longer composed with sounds but composes the sound. Xenak is had already developed this concept of music in his orchestral works Metastaseis (1953-4) and pithoprakta (1955-6), before his electroacoustic experience--his first electroacousitc piece is Diamorphoses (1957).

More generally, speaking about the composers who emerged in the 195 Os, we note that the introduction of the new technology in music did not introduce an historical or stylistic rupture: works can be very similar in their conception, whether they use this technology or not. Of course, as Agostino Di Scipio argues, the dimension of the techne is very important, (5) but the techne includes all compositional technique, and cannot be reduced to the new music technologies. I will say with Theodor Adorno that the evolution of the new, electroacoustic means of artistic production converged with the independent evolution of music itself. (6)

This paper will try to uphold this point of view by dealing with an exceptional case, in which Xenakis, in the late 1960s and the beginning of the 1970s, transposed to his instrumental music an experience with electronic music. We will see that even in this case--where the compositional idea resulted directly from an experience with technology--the compositional practice maintains its autonomy.

THE ORIGINS OF "BROWNIAN MOVEMENTS" IN XENAKIS'S MUSIC

Xenakis first used a computer for sound synthesis at Indiana University in Bloomington (USA), in the end of the 1960s. Reestablishing the probabilistic way of thinking of his early work, he conceived a radically new method of synthesis. As is well known, during that time, methods for sound synthesis were dominated by Fourier analysis. In his article "New Proposals in Microsound Structure," (7) Xenakis rejects these methods, for many reasons, including the perception that the Fourier analysis is related to tonal music. The most important reason was that harmonic analysis "lies in the improvised entanglement of notions of finity and infinity [ . . .] To summarize, we expect that by judiciously piling up simple elements (pure sounds, sine functions) we will create any desired sounds (pressure curve), even those that come close to very strong irregularities--almost stochastic ones. [ . . .] In general, and regardless of the specific function of the unit element, this procedure can be called synthesis by finite j uxtaposed elements. In my opinion it is from here that the deep contradictions stem that should prevent us from using it." (8) This is why he proposes proceeding the inverse way: to start directly from the pressure curves, defined by means of complex, stochastic methods: ". . . we wish to construct sounds with continuous variations that are not made out of unit elements. This method would use stochastic variations of the sound pressure directly." (9) To do so, he uses several probabilistic functions (random walks) and gives some graphical examples of pressure curves calculated by such functions. Example 1 shows a pressure curve calculated with "exponential x Cauchy densities with barriers and Randomized Time." (10)