11. Spectral music

he changes them. This reassures his fans: Xenakis was a musician, not a machine. Personally, I am less reassured. By altering tones at random he mixes formal, conceptional processes with memory - and inspiration - controlled good taste, thereby undermining both the rationale of his own concepts and the synthesis of art and science he advocated.

Here we may come across a basic error in the stochastic principles of Xenakis. To clarify this, let’s assume a sound field of a certain density. With high density we indeed hear the tone field Xenakis strives for, but when density is low the result is a list of possible tones. These are made final by probability calculations but they sound as ordinary, desired pitches. So, they behave as important sources of information but are not designed as such and this is evident when hearing them. To put it simply, in terms of pitch, these pieces sometimes simply sound completely at random (for example in Achoripsis) and bear a peculiar resemblance to the sound of early strict serial works, so fundamentally criticised by Xenakis. In works of great density, however, with large orchestras or a great many tones per second, the results are often impressive and his structures indeed create the sound fields he is aiming for. See Ex. 63 on colour pages XVII-XIX for a visualised example of a meticulous graphic representation of Pithoprakta (1955-56) for orchestra.

11. SPECTRAL MUSIC180

Spectral music is one of the major reactions to the method of serial composition. In the 1970s, criticism of the completely chromatic seriality grew. Composers such as Gérard Grisey (1946-1998) and Tristan Murail (1947) concluded that the harmonic aspect in music had lost a personality and colour of its own.

Like the composers Ligeti and Lutosławski, the spectralists wanted to approach sound as one entity, not as a sum of different, serially ordered parameters. Joshua Fineberg181 put it like this: “Music is ultimately sound evolving in time.”

180This chapter is for the most part based on:

Anthony Cornicello: An Introduction to Spectral Music and Timbre and Structure in Tristan Murail’s Dèsintégrations, (2000), and Daniel Pressnitzer and Stephen

McAdams: ‘Acoustics, psychoacoustics and spectral music’ (2000). 181J. Fineberg: An American composer (born 1969) who lived in Paris between 1991 and 1997. He was a student of Tristan Murail and also worked as a lecturer at IRCAM.