Cardiff University School of Physics Lecture: Sound Synthesis Course Convenor: Professor Mike Greenhough Spring Semester 2005

Principles and techniques of Spectral music

Written by: Justin Lepany Senghennydd Court D-6-1 Salisbury Road CF 24 4 DS

School of Music Student Number:

Content

1. Introduction

2. , spectrum and envelope

3. Instrumental synthesis and its different models

4. Formalization of spectral music

5. Conclus ion

Appendix

References

2 1. Introduction

Spectral m usic – also called spectralism - appeared in the early 1970’s. To describe it in a short and rough way, it is a m usic based on the sound itself. It was created as a possible solution to problems of serial music and . For many , serial music of that time was too strict and abstract: the concept ualization was steady but the result was completely unpredictable and the listener’s perception was thus neglected, as well as sonority, timbre. On the opposite, electronic music of that time was of course based directly on sounds but lacked some writing and organization principles due to the use of “already made” sounds. The spectralists’ goal was to create a music that would reconcile sonority and formalization. By the way, spectral music was to rehabilitate consonance without looking back to the tonal era. This issue was however discussed from the 1960’s on and some composers as famous as Gyorgy Ligeti, or Krzysztof

Penderecki had already been trying to find a balance bet ween sound and conceptualization.

What started spectral music off were the great achievements of modern acoustic since they gave access to the inside of sounds through devices as the spectrograph which analyses a sound and can give a three-dimensional image of it, i.e. the frequencies, their dynamic and their behaviour in time.

The Spectral m usic concept appeared under three different forms in different European places more or less at the same time, around 1973. The first and most famous case is the French school composed of a few ’s pupils whose most well-known composers are Gerard

Grisey (1946-1998) and (b. 1947). At the same time, a spectral trend appeared in

Germany with the group Feedback (Peter Eötvös, Mesias Maiguashca, etc.) whose members are mostly some ’s disciples. The last trend started off in Romania and its main representative is Horatiu Radulescu (b. 1942).

3 The present work aims to present a few essential aspects of composition in spectral music, namely instrumental synthesis of various sound models and the use of process musical form. The first section briefly defines timbre to provide the reader with a few notions necessary to understand spectral music. The second section explains instrumental synthesis and the third section finally shows what kind of procedures spectral music composers use to formalize their pieces.

2. Timbre, s pectrum and envelope

In Spectral music, the first step of the composition process is the analysis of the sound with a spectrograph. Looking into the spectrogram, the can seize the characteristics of the timbre.

Timbre (Lat.: tonus) is the tonal quality of a sound, i.e. what enables one to distinguish a and a flute playing the same pitch at the same loudness. A sound heard as a pitch is actually an ensemble of resonating frequencies: the fundamental and the . If the overtones are whole multiples of the fundamental then they are called harmonics and the spectrum is harmonic. This is the case of pitched instruments like the horn or the . If the overtones are not integer multiple of the fundamental then the overtones are called partials and the spectrum is defined as inharmonic. In different extend, this is the case of bells, percussions or noises, from the waves to artificial white noise which is a sound consisting of all audible frequencies heard with equal intensity. The behaviour in time of the spectrum defines the timbre of a sound.

Another definition of timbre is the envelope, which is the shape of a sound’s amplitude in time. An envelope is characterized by its attack, its steady state and its decay. For instance, the envelope of a violin’s note features a loud attack due to the bow touching the string and a very short decay since the string almost completely stops to vibrate as soon as the bow is not in contact with the string anymore.

4 These details are all important for the composer of spectral music since his music aims to be as close as possible to a sound model.

3. Instrumental synthesis and its different models

Instrumental synthesis consists of using the orchestra as a mean to synthesise sounds. It basically features three types of models: instrumental , inharmonic spectrum and electronic music devices. The instrument model is the most current case: having first analysed the spectrum of a chosen instrument, the composer orchestrates the spectrum, i.e. he assigns the spectrum’s harmonics to every instruments of the orchestra. This procedure is outstanding since the instruments are not considered as a part of a group anymore (brass, strings, etc.) and are not freely selected according to the composer’s taste or for their cultural connotation (the shepherd’s flute, the melancholic , etc.): every single instrument is chosen according to its ability to sound an 's pitch in the best way, i.e. when its range and its sound in a specific part of this very range enables the note to sound as close as an overtone as possible.

After this selection phase, the composer must write the part of every voice in a way that simulates the behaviour in time of every harmonics: the dynamic signs, the , the durations and the rests are selected in that purpose. In order to be as close to reality as possible, this step requires the use of very precise notation such as quartertones and eigthtones. An important point to be mentioned is that spectral music aims to make an orchestra sound like a timbre but not like an exact phenomenon. A two-seconds sound can be the model for a ten minutes piece and therefore will be streched and expanded by the composer.

The most famous example of instrumental synthesis of an instrument sound is Partiels (1975) by

Gérard Grisey. This piece belongs to a six-piece cycle (Prologue, Périodes, Partiels, Modulations,

5 Transitoires and Epilogue) written bet ween 1974 and 1985, which is some kind of anthology of the spectral music techniques. The beginning of this 18-minutes-long piece is based on the simulation of a low E. On the example 1, one can see that the three first bars are just made of a long low E played by the trombone doubled by the double bass. Then, after the introduction of the model itself, starts the orchestral expanded simulation of this very model.

Example 1: the beginning of Partiels

Source: Grisey ( 1975) "Partiels", Paris: Ed. Ricordi.

The second kind of model is inharmonic spectrum. The steps to follow are the same as with harmonic spectrum. An example of musical synthesis of an inharmonic model is Gondwana (1980) by Tristan Murail in which a bell spectrum is used. This piece is explained with more details in a further paragraph.

6 The third model for instrumental synthesis is the simulation of electronic devices. A common case is the use of amplitude modulation, frequency modulation and ring modulation's algorithm to generate artificial spectrums. Many other electronic music devices can be taken as models.

Tristan Murail's Mémoires-Erosions (1975-76) for horn and nine instruments is an outstanding case which aims to transcribe feedback. M urail is the only composer who is named in this section of the present work since he is also well known to be deeply involved in live electronic music and, as a consequence, has composed some of the best spectral pieces among those featuring instrumental synthesis of electronic devices. Back in the early days of electronic music, feedback was made with one tape player and one tape recorder linked together. A signal would be sent to the tape recorder which would record it and send it to the tape player. The former would then send it back to the tape recorder which would be feeded in the meanwhile by some others signals. The result is a sounds mixture that gets richer and richer.

This process is exploited in Mém oire ('Memory'), which is the first part of the piece. This kind of feedback was a complex procedure: after a while, the tape would start to wear out due to an excessive amount of re-recordings and what would come out the tape player would progressively sound like noise rather than a rich polyphony. The second part of the piece, called Erosion, simulates the described process. Appendix 2 shows the first eight loops of the piece where one can see the horn playing different short motifs one after the other. Every motif is then repeated by the different instruments as the horn keeps on playing some new motifs which are also repeated, and so on.

Apart of this outstanding case, many other electronic devices have been simulated : Mémoire-

Erosion simulates delay as well. Appendix 3 shows that some marks are placed below

7 every bar for an instrument to simulate a delay effect. In some other pieces, one can find some reverb or even some phaser simulation.

4. Formalization of s pectral music

The last great feature of spectral music is its particular vision of the musical formalization.

Instead of using the usual narrative forms like sonata or variations, it exploits the sound completely and generates the form from the sound’s envelope. Looking into the sonogram of a five-seconds- long piano note, one can see that the behaviour in time of every component is different: for example, some overtones are first dominant, then disappear and appear again but less loud. The composer can expand the general shape in duration to get obtain the general form of the piece as well the climaxes and the quite moments. The compression in time of the behaviour of single components can inspire the rhythms of an instrumental line, et cetera. This procedure was used during the spectralism’s very first years and was then often replaced by another one that had already been used by composer like Stockhause: processes.

The use of processes in m usic is firstly the definition of t wo states: the primal one and the final one.

The composition procedure then takes the composer to transform the primal state into the final one, making the changes as subtle and as indiscernible as possible. Tristan Murail gives us a clear example in his piece Gondwana for an ensem ble of wood instruments, brass instruments and resonating instruments (piano, vibraphone and crotales), composed and performed in 1980 (see appendix 2). In the first part, the primal model is a bell sound and the final model is a trumpet note.

In bet ween are ten different intermediate states of which the transitions from one to the other slowly melt the virtual bell sound into a virtual trumpet sound. This transformation has other underlying meanings as this piece is also the transit from an inharmonic spectrum to a harmonic spectrum.

8 5. Conclusion

Even though spectralists try to be rigorous and more or less scientific, there are two facts that make any hope of real instrumental synthesis utopian: First, acoustic instruments don't produce sine waves but complex sounds and therefore can't sound overtones. Second, the use of tempered instruments, rythmns patterns and dynamic marks can not render a realistic imitation of the pitch, the loudness and the duration of an overtone, even if the composer demands quartertones or eighthtones and use some very thorough notations. Anyone who aims to synthesise timbre with acoustic instruments and human musicians is unfort unatly doomed to failure.

The french composer Philippe Manoury once put the matter in a nutshell by writing about spectral music, that “there are not more spectrum in this music than in any other music” (Deliège 1998, p.803).

Nevertheless, even if the quest for a new music entirely inspired by the sound itself was a disapointement, spectral music is still a very special music with a very unique aesthetic. Its mysterious and slow sonorities still fascinate the audiences and the composers of today. More than thirty years after the first spectral pieces, spectral m usic influences many composers from different schools. Such a fact is rare enough in the field of contemporary music and to be mentionned as well as remembered.

9 Appendix

Appendix 1: Cohen-Levinas, Danielle (1998) "L'itinéraire", Paris: L'Harmattan, p.108.

10 Appendix 2: Cohen-Levinas, Danielle (1998) "L'itinéraire", Paris: L'Harmattan, p.109.

11 References

Barrière, Jean-Baptiste (1991) "Le timbre, métaphore pour la composition", Paris: I.R.C.A.M et

Christian Bourgeois Editeur.

Cohen-Levinas, Danielle (1998) "L'itinéraire", Paris: L'Harmattan.

Deliège, Célestin (2003) "Cinquante ans de modernité musicale", Paris: Pierre Mardaga.

Dufourt, Hugues (1991) "Musique, Pouvoir, Écriture", Paris: Bourgeois.

Fichet, Laurent (1996) Les théories scientifiques de la musique au XIXe et XXe siècles", Paris: J.

Vrin.

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