Silvio Ferraz

University of São Paulo, Brazil;


In 1958, in the drafts of Concret PH (as observed by Makis Solomos), Iannis Xenakis notes that “a music is a set of energetic transformations”. In 1968 Xenakis, this notion of energy appears as a thematic in the composition of Kraneerg, (kraan. – to accomplish and erg.- energy) and from the 1990s, more precisely in 1994, the notion of energy gains more strength in the text as “Sur le temps” and “Conversation” with Morton Feldman, by noting that “the problem of composition is how to use this energy” and further adding that energy can be in the “combination of sounds, the timbre, the rhythms, the length, and the tempo of the piece”. Recently, the study of the notion of energy in Xenakis has received some studies by Makis Solomos, Christoph Casagrande and Mikhail Malt. Solomos gives a reading of the notion in Xenakis’ thought, Malt and Casagrande deal specifically with works. Malt analyzes Bohor and looks at the energy manifested in the evolution curve of sound intensity, Casagrande analyzes the set of forces present in Krannerg: iterative, granular/ chaotic, fusion/fissionary, massic and the pulsative forces. Such forces are found in other works by the composer and corroborate the idea of thinking about energy from the tendencies of its elementary components. A compositional thought that starts from the “corpuscle-sounds with their spins” (units of measure of angular momentum of elementary particles), as Xenakis proposes in his article “Musique et Originalité”. In order to think about energy from the elementary components and the intensity curve, it is worth bringing Xenakis’ thought closer to the study on the idea of “potential energy” as studied by Gilbert Simondon. Simondon relates energy to isotropic or anisotropic distribution of elementary components, an idea very close to the one Xenakis employs whit the notion of entropy from the ataxia functions on the time and frequency axes. Thus, a system is isotropic according to the symmetry of distribution of elements. And anisotropic, when the tendencies of its components are not symmetric. Thus, isotropic systems indicate an equilibrium of all their components in a way that does not show a trend of transformation, corresponding to a stasis of the system. The anisotropy of a system, on the other hand, would clearly indicate its kinesis, the presence of privileged directions of the system. To address such a question, I present a study of the quartet ST/4-1, 02061962, a rewritten of ST/10-1, 080262, observing the distribution of the dynamic elements at each moment of the piece: the sound-corpuscles and their spins. Spins are related to the tendencies not only of microparticles (as in the glissandi), but also the general flow of the composition distinguishing the isotropy/anisotropy of the moments that formally constitute the piece, and in the passages between such moments. In this sense, I distinguish the configurations (nuages, Cf. Xenakis, “Les chemins de la composition musicale”), and their potential energy relative to the kinesi/stasi balance of musical flow in Xenakis’ string quartet.

Keywords: Musical Energy; Iannis Xenakis; Gilbert Simondon; ST-/4-1.


Silvio Ferraz is Professor at the Music Department of the University of São Paulo. Between 2002 and 2013 he served as Associate Professor of the music department of the Institute of Arts at UNICAMP, in the biennium 2009-2010 was Pedagogical Director of the School of Music of the State of São Paulo and Director of the Campos do Jordão International Winter Festival. Voluntary professor of the graduate program in Music at ECA-USP (2009-2010). Coordinated the Center for Musical Language (PUCSP), the virtual Institute MusArtS (musica articulata sciencia), Núcleo de Integração e Difusão Cultural (NIDIC-UNICAMP) and the Graduate Program in Music at Unicamp (2013). He currently coordinates the ECA-USP/Unvieristée Paris 8 Agreement and has participated annually in international congresses as a Lecturer.