The unity of Xenakis’ instrumental and electroacoustic music. The case of “brownian movements”

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music. The case of “brownian movements”

Makis Solomos

To cite this version:

Makis Solomos. The unity of Xenakis’ instrumental and electroacoustic music. The case of “brownian movements”. Perspectives of New Music, New Music, Inc., 2001. �hal-01789832�

The unity of Xenakis’ instrumental and electroacoustic music. The case of the “Brownian movements”

Makis Solomos

Perspectives of New Music vol. 39 n°1, 2001, p. 244-254.

Technology and the autonomy of compositional practice

Xenakis’ instrumental music (including also vocal music) has already been studied in a lot of articles, reviews and even books

. For his electroacoustic music —I use here the historical word, including in it also the pure electronic music— there are for the moment only a few analysis

. And as for the relationships between his instrumental and his electroacoustic music, we only have general commentaries. This is only to say that the present paper is a calling for further analysis. Indeed, in an attempt to show the unity of Xenakis’ instrumental and electroacoustic music, I will only focus on a special topic: the influence of Xenakis’

experience with random walks for sound synthesis in the late 1960s, to his instrumental pieces of the 1970s.

This special topic has to be connected with one general question: what is the part of the influence of music technology to music itself? 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 beginnings,

“explored the possibilities of simulating electronically produced sounds and sonorities with conventional instruments”

. Hugues Dufourt, probably thinking to his own music and to

“spectral music”, repeated the same statement

. However, this is not exact. It is true that the electroacoustic practice of the 1950s made Ligeti, Stockhausen or Berio discover radical new ways of conceiving music in general and, consequently, that they applied them in their instrumental music. But Xenakis is more like Varèse, who wrote radically new music before

1 See the commented bibliography in Makis Solomos (ed.), Présences de Iannis Xenakis / Presences of Iannis Xenakis (Paris: CDMC, 2001), 231-265, also on www.iannis-xenakis.org.

2 I quote the most important ones: Agostino Di Scipio, “Compositional Models in Xenakis’s Electroacoustic Music”, Perspectives of New Music 36 no. 2 (1998): 201-243, “The problem of 2nd-order sonorities in Xenakis' electroacoustic music”, Organised Sound 2 no. 3 (1997): 165-178; Peter Hoffmann, “Analysis through Resynthesis. Gendy3 by Iannis Xenakis”, in Présences de Iannis Xenakis (op. cit.), 185-194; Peter Hoffman, Makis Solomos, “The Electroacoustic Music of Xenakis”, in Proceedings of the First Symposium on Computer and Music (Corfu: Ionian University, 1998) 86-94; Herbert Ruscol, The Liberation of Sound. An introduction to Electronic Music (Prentice-Hall International, 1972), 154-162, 233-237; Pierre Schaeffer, La musique concrète (Paris: PUF/Que Sais-Je, 1967), 81-82; Makis Solomos, A propos des premières œuvres (1953-1969) de I.

Xenakis (Ph.D. dissertation, Université Paris 4, 1993), 263-272; Ronald J. Squibbs, “Images of Sound in Xenakis' Mycenae-Alpha”, in Gérard Assayag, Marc Chemillier, Chistian Eloy (ed.), Troisièmes journées d'informatique musicale JIM 96 = Les cahiers du GREYC 4 (1996): 208-219; Stefania de Stefano,

“Spettromorfologie e articolazione strutturale in Diamorphoses (1957) di Iannis Xenakis”, in M.C. De Amicis (ed), Atti del Congresso di Dittatica della musical elettronica (L'Aquila: Instituto Gramma, 1998), 131-133. We have to add also articles refering to Xenakis’ technological innovations, the UPIC and the GENDYN program; I quote only some: Peter Hoffmann, “Implementing the Dynamic Stochastic Synthesis”, in Gérard Assayag, Marc Chemillier, Chistian Eloy (éd.), op. cit., 341-347; Gérard Marino, Marie-Hélène Serra, Jean-Michel Raczinski,

“The UPIC System: Origins and Innovations”, Perspectives of New Music 31 no. 1 (1991): 258-269; Marie- Hélène Serra, “Stochastic Composition and Stochastic Timbre: GENDY 3 by Iannis Xenakis”, Perspectives of New Music 31 no. 1 (1993): 236-257.

3 David Ewen, Composers of Tomorrow’s Music (New York : Dodd Mean and Co, 1971), 125.

4 See Hugues Dufourt, “Hauteur et timbre”, Inharmoniques 3 (1988): 69.

the introduction of the new technology, a music that is no more composed with sounds but composes the sound. Xenakis developed this concept of music already in his orchestral works Metastaseis (1953-54) and Pithoprakta (1955-56), i.e. before his electroacoustic experience

—his first electroacoustic piece is Diamorphoses (1957).

More generally, and speaking again about the other composers who emerged in the 1950s, we can notice that the introduction of the new technology (i.e. the means of electroacoustic music of this epoch) in music didn’t cause a breaking: works which use or not use this technology can be very similar in their conception. Of course, as argue Agostino Di Scipio, the dimension of the technè is very important

, but the technè includes the whole music technique and can not be reduced to the so-called new music technologies. Coming back to the beginnings of electroacoustic music, I will say with Theodor Adorno that the new means (the electroacoustic one) converged with the evolution of music itself

.

This paper will try to uphold this point of view by dealing with an exceptional case, where Xenakis, in the late 1960s-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 direcly from an experience with technology— the compositional practice keeps its autonomy.

The “Brownian movements” in Xenakis’ music: origins and autonomisation

At Bloomington (USA), in the end of the 1960s, Xenakis can use for the first time a computer for sound synthesis. Reestablishing the probabilistic way of thinking of his beginnings, he conceives a method of synthesis radically new. As well known, during that time, the methods for sound synthesis were dominated by the Fourier harmonic analysis. In his article “New Proposals in Microsound Structure”

, Xenakis rejects these methods, for many reasons —for instance, the fact that the Fourier analysis is related to tonal music. The most important one is that harmonic analysis “lies in the improvised entanglement of notions of finite and infinity […] To summarise, we expect that by judiciously piling up simple elements (pure sounds, sine functions) we will create any desired sounds (pressure curves), 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 juxtaposed elements. In my opinion it is from here that the deep contradiction stem that should prevent us from using it”

. It is why he proposes the inverse way: to start directly from the pressure curves, defined with the 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”

. To do so, he uses several probabilistic functions (random walks) and gives some graphical

5 See Agostino Di Scipio, “Questions concerning music technology”, Angelaki: journal of the theoretical humanities 3 no. 2 (1998): 31-40.

6 See Theodor W. Adorno, “Musik und neue Musik” (1960), Quasi una fantasia, Gesammelte Schriften band 16 (Frankfurt am Main: Suhrkamp, 1978), 476-492.

7 Published in Iannis Xenakis, Formalized Music (Bloomington: University Press, 1971), 242-254 (new edition:

Stuyvesant NY: Pendragon Press, 1992).

8 Ibid, p. 245-246.

9 Ibid, p. 246.

examples of pressure curves calculated by such functions.

calculated with “exponential x Cauchy densities with barriers and Randomised Time”

.

Probably because the computer means in Bloomington or in the just born Parisian CEMAMu

weren’t enough strong, Xenakis didn’t compose at that time a piece using such a sound synthesis method. The first work containing some probabilistic sounds is La Légende d’Eer (1977, music for the Diatope)

. And the two unique pure probabilistic electronic compositions are Gendy 3 (1991) and S.709 (1994): Xenakis had to wait the early 1990s for generalising probabilistic sound synthesis —in the GENDYN program of the CEMAMu

.

Coming back to our period, we can easily imagine that a man like Xenakis, after having invented a radically new method for sound synthesis, couldn’t wait for hearing the result in a composition! As he couldn’t do it so in electronic music, he applied this principle to his instrumental music, in a transfer very characteristic of his way of thinking —do not forget that, initially, the probabilistic methods were applied in instrumental works of the 1950s.

Doing this transfer is very easy. Taking the graphs of probabilistic sound curves, the only think to do is to change their coordinates: the horizontal axis will be allocated to the time of instrumental music and the vertical axis will indicate the pitches —and, finally, the graph will be converted in instrumental notation, as with the graphs of glissandi in the 1950s. The result is, in Xenakis’ terminology for this compositional method, a “Brownian movement”. As well known, Brownian movements are “processes of chaotic movements of small particles suspended in a liquid or a gaze, which are the result of their collision with the molecules of the environment”

—if we can hear Xenakis’ Brownian movements as good metaphors for the Brownian movements of physics is another question!

Mikka (1971, for solo violin) is the first composition using this method. It is also the one in which the Brownian movements (in the sense of Xenakis’ instrumental music) produce sounds that can be compared —using of course another metaphor— to the sounds produced by the aforementioned probabilistic methods. Indeed, the whole piece seems like a random walk. The violin glissandi of Mikka —we have to insist in the role played by the strings for Xenakis: a lot of his compositional innovations were first tested for them— is the perfect metaphor for continuously varied probabilistic sound curves. The continuous glissandi (except for some tenutos) produced with these graphs are very different from the linear, directional glissandi that Xenakis used by the past: their direction and their slope is probabilistic (see

The purists will be shocked by the double transfer that made Xenakis to compose Mikka. First, he started from the image of Brownian movements (in the physical sense) to conceive a new way of sound synthesis. Second, as he couldn’t, at that time, realise a whole piece with such sounds, he transferred the graph of a sound curve to a graph for instrumental

10 Ibid, p.251.

11 Founded in 1966, the EMAMu changed his name into CEMAMU (Centre d'Etudes de Mathématique et Automatique Musicales) in 1972.

12 For these sounds, the calculations were made in the CEMAMu and the sound synthesis in the WDR’s studio.

13 For bibliography about the program GENDYN and the piece Gendy 3, see previous footnote. See also Xenakis’ articles “Dynamic Stochastic Synthesis” and “More Thorough Stochastic Synthesis” in the new edition of Formalized Music (op. cit.), 289-294 and 295-322.

14 Encyclopedia of Mathematics, vol.1 (London: Kluwer Academic Publishers, 1993), 483.

music. But the biggest inventions are very often du to such experimental, empirical methods;

they are very often due to pure chance (in the common and not mathematical sense)! It is the way of physics, biology and all experimental sciences —it is also the way, moreover, of mathematics in a lot of cases. Precisely, with Xenakis —and with some other composers of his generation—, music became partially experimental. A traditional composer is supposed to recreate, by the means of the famous “interior audition”, pre-existing sounds —of course with new combinations. For the composers of the second modernism (post 1945 music), the matter was to produce unheard sounds. The only way for that is experimentation. For instance, it is clear that the famous glissandi of Metastaseis are the pure results of experimentation. We can suppose that Xenakis couldn’t hear them interior, as such sounds didn’t exist before. And he invented them by the means of pure graphs.

To come back to the Brownian movements of Mikka, the purists have to agree that, despite the double transfer, this compositional method (the Brownian movement in the sense of Xenakis’ instrumental music) has autonomy. By listening Mikka, nobody is forced to think immediately to the Brownian movement in the physical sense or to the random sound curves.

The listener can hear the random glissandi of Mikka as pure instrumental music. If his imagination is attached to traditional music, these sounds could remind him East Asian melodies.

The evolution of the Brownian movements

Let’s now have a look to the evolution of this compositional technique in Xenakis’

production. This evolution will confirm the autonomisation of this technique from its sources, the aforementioned double transfer: by some very few changes, the Brownian movements of Mikka will be completely transformed. Xenakis use them in a lot of works of the 1970s, along with other compositional techniques —he stopped use them in the beginning of the 1980s

. Because of the lack of space, I will only study the transformations that happen in N’Shima (1975, for two mezzo, two horns, two trombones and cello

.

Xenakis is very clear in the preface of the score of N’Shima: “The melodic patterns of N’Shima are drawn from a computer-plotted graph as result of Brownian movement (random walk) theory that I introduced into sound synthesis with the computer in the pressure versus time domain”

. Almost the whole piece —and a relatively long one for Xenakis’ standards:

about 17 minutes of music— is produced with such graphs. The original graphs have not been founded for the moment

, but it is not important for the present study. What is important is

15 For a more precise history of the Brownian movements in Xenakis’ compositions, see Makis Solomos, Iannis Xenakis (Mercuès: PO Editions, 199), chapter 2 and 3. Xenakis uses them in Mikka (1971), Cendrées (1973), Phlegra (1975), N’Shima (1975), Theraps (1975-1976), Retours-Windungen (1976), Mikka-S (1976), Epeï (1976), Akanthos (1977), Jonchaies (1977), Ikhoor (1978), Dikhthas (1979), Palimpsest (1979), Anémoessa (1979), Mists (1981), Komboï (1981), Chant des soleils (1983), Tetras (1983), Thalleïn (1984).

16 For a detailed analysis of N’Shima, see Ruth Béatrix Raanan: N'Shima de Iannis Xenakis: composition avec le souffle. Analyse de l'œuvre (mémoire de D.E.A., Ecole des Hautes Etudes en Sciences Sociales/Université Paris IV/IRCAM, 1998); “Le souffle et le texte : deux approches formelles convergentes dans N’Shima de Iannis Xenakis”, in Présences de Iannis Xenakis op. cit.) 173-178.

17 N’Shima, preface of the score, Paris, Salabert.

18 For graphical representations of N’Shima —which recompose the original graphs—, see Ruth Béatrix Raanan, op. cit.

the fact that the Brownian movements of N’Shima are very different, as sound result, from those of Mikka. Figure 3 gives an indication for the execution of the voices tooken from the preface of the score and figure 4 shows an extract of the voices in the score.

The result is very different from the sounds of Mikka for three reasons. First, the ambitus of the glissandi is very small —this case occurs also in Mikka, but it is not the general case—, producing in fact what the tradition calls portamenti, and not glissandi. Second, the glissandi are in general extremely brief —this case is very rare in Mikka. Third, in contrast with Mikka, they are attacked in every point of departure and, moreover, this attack is sforzando. In Mikka the result is very smooth and continuous sound. In N’Shima, we have chiselled sounds, made by a succession of small rhythmical impulses that are very tense. This result is also confirmed by the choice of the medium: in Mikka Xenakis write for a kind of abstract string; in N’Shima he asks for “‘peasant-like’, warm, full-throated, open, round and homogeneous” voices

. The materialisation of the Brownian movements in the horns of N’Shima (see

completely new sounds, sounds that are not anymore heard as results of the aforementioned double transfer, but as totally autonomous instrumentals sounds.

19 N’Shima, preface of the score.