(Fr.: musique spectrale).
A term referring to music composed mainly in Europe since the 1970s which uses the acoustic properties of sound itself (or sound spectra) as the basis of its compositional material. It has come to be associated particularly with the composers of the French Groupe de l'Itinéraire (especially Grisey and Murail), and the German Feedback group, with its principal members Fritsch, Maiguashca, Eötvös, Vivier and Barlow. The term ‘spectral music’, coined by Dufourt in an article of 1979, emphasizes the importance of the sound spectra themselves to the music and its techniques. However, the tendency has also had important ramifications in the fields of form and musical time.
Among the most influential techniques of spectral music has been what Grisey termed ‘instrumental synthesis’. In Grisey's Périodes (1974) for seven instruments the final chord is derived from a sonogram analysis of the spectrum of a trombone's low E, so that the timbre of the trombone is artificially re-synthesized by the rest of the ensemble. Another technique, used by Grisey in Partiels and Murail in Gondwana, involves the instrumental simulation of ring modulation techniques to modulate the music away from and back to pure harmonic spectra. This involves taking pairs of frequencies, calculating their summation and difference tones (as well as the sums and differences of their harmonics, etc.) and using the resultant complex of pitches for the instrumental harmony. The more consonant the relationship between the two generating frequencies (and hence the simpler the numerical relationship of their frequencies) the more consonant and harmonious will be the resultant complex. Ex.1 shows the first frequency modulation complex together with its orchestration at the start of Gondwana. There are two generative frequencies, called carrier and modulator respectively, marked A and B in the example; their respective frequencies are shown in the list below, together with a list of their sum and difference tones which generate all the other pitches in the example. (The microtones used approximate these resultant frequencies to the nearest quarter of a tone.) The refinement and sophistication of the orchestration ensures that this large complex blends into a single, unified timbre of great complexity, and as the relationship between the two generative frequencies is highly dissonant, the resultant complex is correspondingly inharmonic. Over the first part of this piece, the ratio between the pairs of generative frequencies is gradually made more consonant and the resultant spectra modulate towards the stability of the harmonic series. These constant swings between harmonicity and inharmonicity are often mirrored by movements between moments of maximum rhythmic regularity (or ‘periodicity’) and maximum irregularity (or ‘aperiodicity’). Indeed, the first major theoretical article on spectral music, Grisey's Tempus ex machina was a treatise not on spectra themselves, but rather on musical time and its compositional deployment.
The work of the Feedback group, made up largely of ex-students of Stockhausen, shares with that of Grisey and Murail a concern for the reassessment of consonance and the exploration, within an instrumental context, of techniques derived from the analogue electronic studio, notably that of ring modulation. Unlike in the earlier work of Grisey and Murail, however, the result is often strikingly melodic and linear as well as harmonic in content. Typical examples of this style include FMelodies (1981) and Monodias e interludios (1984) by Maiguashca, whose melodic and harmonic material is entirely derived from a large collection of spectra whose frequencies are related to each other by sum and difference, ranging from the extremely dissonant and enharmonic to the entirely consonant and harmonic. Similar procedures are used to generate the pitch material for Eötvös's A Chinese Opera (1986), while Vivier's Lonely Child (1980), Bouchara (1981) and Prologue pour un Marco Polo (1981), combine a melodic style of disarming, even childlike simplicity, with non-tempered spectra (modelled on ring modulation) of extraordinary richness and complexity.
In parallel with the two main schools of spectral thought, analogous techniques and aesthetics have appeared elsewhere. An independent type of spectral composition sprang up in Romania in the 1970s, both in the work of Niculescu and Ioachimescu, in which spectral concerns are linked to diatonicism and folk-influenced modality, and in the work of more experimental composers such as Dumitrescu and Radulescu. Radulescu's personal theory of composition, evolved in the early 1970s, focusses on the status of ‘sound plasmas’ – frequency complexes generated either from ring modulation or from large pitch collections which are harmonics of some very low theoretical fundamental sound. Aspects of this theory have touched such younger European composers as Dillon and Tanguy.
A number of composers have been influenced by the techniques and aesthetics of spectral music without being drawn to them exclusively: these include Saariaho, Jonathan Harvey and pupils of Grisey and Murail, such as Lindberg, Dalbavie and Hurel. Other members of L'Itinéraire, such as Dufourt and Levinas, have shown greater freedom in their interpretation of the aesthetic; Dufourt has even attempted a highly personal fusion of serial and spectral techniques, with questions of harmony determined by the former techniques and questions of spacing, orchestration and pacing more determined by the latter. Indeed, beginning in the late 1980s, many of the originators of spectral music began to move away from the strictest application of its techniques, evolving more ambiguous musical syntaxes as a result. Grisey and Murail especially, in their works of the late 1980s and early 90s, avoided the smooth processes characteristic of their earliest mature work, focussing instead on discontinuity and unpredictable forms, with a new emphasis on linear, polyphonic writing. It is perhaps no coincidence that both turned during this period to writing for the voice, Murail in Les sept paroles du Christ en croix (1989) and Grisey's in his Quatre chants pour franchir le seuil (1998).
H. Radulescu: Sound Plasma: Music of the Future Sign: or, My D High: Op.19 [Symbol for Infinity] (Munich, 1975)
G. Grisey: ‘Tempus ex machina: a Composer's Reflections on Musical Time’, CMR, ii/1 (1987), 238–75
Entretemps, no.8 (1989) [spectral music issue]
R. Rose: ‘Introduction to the Pitch Organization in French Spectral Music’, PNM, xxxiv/2 (1996), 6–39
J. Fineberg, ed.: ‘Spectral Music I–II’, CMR, xix/2–3 (2000) [2 complete issues]
JULIAN ANDERSON
