Spectral music is now more than forty years old. In his preface, French composer and philosopher Hugues Dufourt defines it thus:

After reading this introductory passage, coming as it does from the person who coined the term ‘musique spectrale’ (in his famous 1979 manifesto),Footnote ¹ the reader might expect a book that takes stock of the state of this compositional movement, exploring its protagonists and historical development – a sort of handbook of spectral music. In fact, this volume reunites a series of essays composed by Dufourt over the course of twenty years and should be read accordingly. As a collection of older as well as more recent articles dealing with spectralism-related questions, the book slips between historical, analytical, phenomenological, and auto-biographical approaches.

Placing himself in the dual role of editor and contributor, Dufourt begins by introducing the underlying themes and motivations:

Predecessors, categories of musical thought, and the bond between art, science, and technology – these are the themes discussed at length across sixteen chapters, each of which was originally an article, concert programme note, or conference paper written between 1995 and 2013. All the chapters have already been published elsewhere, except for three: the long first one (almost 100 pages) which is also the most recent (written in September 2013), an article on Pierre Boulez, and the final chapter, a conference paper presented in 2010 at the Festival Milano Musica. Although all the chapters are stand-alone pieces and seem arranged in a loosely connected and non-chronological sequence – a characteristic which enables readers to encounter them in a different order depending on their own specific interests – the book can nevertheless be seen as a coherent whole, written from an insider's point of view.

The book opens with a long disquisition (‘La violence de l'art’) on the specificity of spectral music, addressing its historical, aesthetic, technological, and epistemological meanings. The ‘articulation en puissance’ of movement, quality, and masses; sound as energy rather than number; the dynamism of transitions rather than montage; form arising from its material – these form the essential themes that recur throughout the book (18). The volume continues with single chapters dedicated to Stravinsky, Schoenberg, Boulez, the principles of spectral music, Bauhaus and IRCAM, Pierre Schaeffer, elites and programmes, computer music, musical space, musical material as genetic source of movement and space, intensity and timbre as carriers of form, Gérard Grisey and the meaning of his musical production, the theoretical and philosophical foundations of spectral music, and finally the contradictions and fertility of the spectral model.

The first chapter thus acts as an introduction to the previously written articles that follow it here. From the second chapter onwards, the contents are focused on three main themes: specific composers (predecessors, and the initiator of spectral music, Gérard Grisey), compositional principles, and Dufourt's philosophical discussion of scientific knowledge and its interconnection with art, in the attempt, as seen above, ‘to disengage the epistemological basis’ (11) of such connections.

Spectral music, therefore, is not strictly the only subject of this book. The second and third chapters, for instance, focus on Stravinsky and Schoenberg. If Stravinsky has ‘a certain tendency to the momentary’ (118) as depicted by Dahlhaus, and discrete scales and simultaneity are his materials, then Schoenberg's theory of composition is closely related to his philosophy of religion: ‘for Schoenberg, a composer is an inspired spirit, whose poetic power manifests itself first in the form of an instantaneous synoptic intuition’ (135). ‘I compose by beginning with a vision of the whole’, writes Schoenberg, ‘and then tie down the details’ – an idea that Dufourt summarizes as one in which ‘the organized elements of musical writing are all integrated into a hierarchy of functions where the whole dominates the parts’ (135). ‘L'Emancipation gnostique du timbre chez Schoenberg’ concludes with Adorno's interpretation of Schoenberg's music and Schoenberg's own ideas on Debussy (one of the pivotal figures in the prehistory of spectral music), whose fourth chords and whole-tone scales were responsible for a ‘softening of the expressive power and, in the long term, the elimination of all characterization’, in the harsh words of the Austrian composer's Harmonielehre (157). The following chapter on Boulez (published here for the first time, though written in 1996) is a discussion of serial music and its failure: this music, ‘by assuming the simultaneous validity of equally restrictive norms – the parametric organization of pitches, durations, timbres – was unable to reconcile different kinds of representation, which became irreducible’ (175). But it also presents the innovative idea embodied in serialism: the abolition of the distinction between the vertical and the horizontal, which brings with it interferences, ambiguities, and imperceptible transitions between distinct categories (179), all concepts very dear to spectral composers. Dufourt returns to the topic of serial music, viewed as both a technique and a doctrine, in ‘Les principes de les musiques sérielles’. (A small endnote acknowledges Fabien Lévy for his suggestions on the sections dealing with the relation between music and mathematics.Footnote ²) ‘Le Bauhaus et l'Ircam: deux maisons de la Construction au XX^e siècle’ (first published in 1998) is divided into two parts: the first is about the Bauhaus, the second is devoted to IRCAM, its parallels with and differences from the German art school, and the relationship between art, science, and technology more generally. An ensuing chapter analysing Pierre Schaeffer is an attempt to read the Traité des objets musicaux as a philosophical system. Dufourt outlines the dignity of contemplation, the religious vocation of art, the persistence of Pythagorean thought, and the idea of music as a space of ecstasy that results from the exceeding of the rational activity of thought (227). The next chapter, ‘Élites et programmes’, addresses Adorno's theories of avant-garde music after 1945, and concludes – in Dufourt's words – that Adorno's vision must be revised: composers such as Luigi Nono, Bernd Alois Zimmerman, Helmut Lachenmann, György Kurtag, and others ‘envisaged a renewal of compositional techniques as a symbolic adventure in solidarity with the enterprise of social change’, an adventure culminating in the computer research developed by John Chowning and Jean-Claude Risset (252–3).

Dufourt turns to computers in ‘La musique sur ordinateur: une sémantique sans sujet?’, which discusses the implications of the encounter between computers and music in relation to Leibnitz, proceeding to debate the work of perception psychologists James J. Gibson, Roger N. Shepard, and Albert S. Bregman, and dedicating six pages to Risset's important contribution in this area. Computer music, writes Dufourt,

This is also the only chapter completed by a list of bibliographical references divided according to the different domains of computer music: signal processing, computer synthesis, automated composition, and so on.

With the tenth chapter, written in 1998 and dedicated to the idea of acoustic space, the book finally presents its main theme – spectral music. It does so tangentially, through the introduction of crucial compositional categories. Acoustic space is one of these, as already investigated by Berlioz, Debussy, and Ravel (279), and later in avant-garde music after 1945. Mutations by Risset (1969) is seen as a pivotal work (282), followed by the music of Tristan Murail, Grisey, and Michaël Levinas as well as Dufourt's own work: this ‘quartet’ of composers is thus mentioned here for only the second time, more than halfway through the book (283). Dufourt also finally describes here the five principles of spectral music: 1) the computer makes it possible to compose/decompose sound; 2) harmony is transformed into timbre; 3) form and material become one; 4) synthesis and sound processing cannot be separated from research into listening-perception; 5) form has a deep bond with structure (284–9). The next chapter, though written in 2005, seems to be a seamless continuation of the previous one, introducing musical material as a genetic dynamic source of sound and space. ‘L'action spatialisante en musique’ is seen here as a direct consequence of the musical research of the first half of the twentieth century (Debussy, in the first instance) and the ‘genetic dynamism of material’ typified by Cubism and Russian Constructivism, and later by Stockhausen (in Gesang der Jünglinge) and Grisey. The concepts of continuum and (physical) space as a simulation of the physical area are also introduced here.

The following chapter assesses the concepts of timbre and intensity. Dufourt examines the implications of (musical) science and the modelling of timbre; Mathews, Risset, Chowning, Pierce, Wessel, Bregman, McAdams, Moorer, Moog, and Arfib are all mentioned in quick succession here, as well as Varèse, Messiaen, Xenakis, and Ligeti, to stress the broad evolution of this investigation. The next chapter is dedicated solely to Grisey and offers a sequence of interpretations (each section is one or two pages long) of Grisey's Bergsonism, neo-serial polemics, timbre, structure, and musical writing, ‘énergétique musicale’, time and synthesis (with acoustic instruments), sounds and shadow-sounds. The subsequent chapter is titled ‘The meaning of Grisey's work’, a hommage presented by Dufourt in Milan in 2008. Noting Grisey's refusal both of patronage and of the need for others to comment on his work (375), Dufourt nonetheless sets out to analyse his colleague's music, returning to some of the notions touched on in the previous chapter, and separating the first phase from the period after Espaces acoustiques.

In the penultimate chapter (written in 2003), Dufourt debates the theoretical and philosophical bases of spectral music, including technical and mathematical questions, and issues of computer science; he offers for the first time here a personal interpretation of Grisey's and Murail's approaches to spectral music as opposed to that of Lévinas (418–19), writing that ‘[t]he philosophy of continuum shared by Grisey, Murail, Lévinas and me, expresses a refusal of any metaphysical theories of music, counting among them the combinatory approach, the contrapuntal spirit, and all varieties of formalism’ (422). Terms such as ‘mixture’ and ‘ambiguity’ return repeatedly, as do the names of Chowning and Risset. The final chapter, an unpublished paper given at a 2010 symposium dedicated to spectral music organized by Gianmario Borio and Alessandro Melchiorre, is titled ‘Contradictions and fecundity of spectral music’ and is the most personal account found within the book, written in the first person. Here, Dufourt narrates the history of the term ‘spectral’ (457–8). He reconstructs the early steps he and his colleagues took, and cites several early works. ‘To me, spectral music would not have been possible without the transformation introduced by sound synthesis’, Dufourt writes, and he mentions the studies of Mathews, Pierce, Risset, Chowning, Moorer, Grey, and many others. ‘With computers, music has changed its scale altogether’ (461). But computer synthesis is not a cold language, he argues; it taught spectral composers that sound is an ensemble of dynamic characteristics in constant interaction, ‘spectral music is a discipline of writing, not of applied logic’ (464). There is an energy, ‘an intuition of energy’, within this dynamic interaction of forces, he claims, adding that ‘our reference-points inside L'Itinéraire were neither linguistic nor biological’ (468). This chapter thus provides an appropriate close to the remarkable breadth of enquiry presented in the book.

The reader might wonder why Dufourt did not include here his groundbreaking article/manifesto ‘Musique spectrale’ (1979), republished so many times, in which he coined the term and launched the new movement. The reasons remain mysterious, even though the essay would have helped give a further perspective on spectral music.

As set out above, Hugues Dufourt the editor prefers not to dictate how to read Dufourt the contributor. The reader, however, has other options at his/her disposal: the final index of names. To this extent, the index (although occasionally imprecise) may encourage the reader to find out much more about the ‘content’ of the book, serving as a kind of Ariadne's thread. It is certainly useful to cast a glance at it. Philosophers such as Adorno and Leibnitz leave their mark throughout the entire book (thirty and fourteen entries, respectively). Schoenberg, Boulez, and Murail, and of course the tutelary Grisey are all important references, as might be expected. Among other composers cited throughout the book, Schaeffer, Stockhausen, and Xenakis stand out most prominently.

The index also underlines the importance of the research work of Chowning (forty-six entries) and Risset (seventy-seven entries) – whose ambiguous notion of the short-circuit ‘harmony–timbre–harmony’ is strikingly demonstrated in pieces such as Stria or Mutations – as well as Jean-Baptiste Joseph Fourier, Hermann von Helmholtz, Max Mathews, Stephen McAdams, John Pierce, and David Wessel. It is with names such as these that the reader can follow the special links spectral music has with technological and psychoacoustic research. This is the basis of the true epistemological revolution to which Dufourt refers in the book's subtitle. As Dufourt said during a radio interview in 2016, thanks to the use of computer, ‘by changing scale, music has changed its language. Timbral objects, found for example by Risset, are essentially models of knowledge of certain acoustic phenomena. These are artifices of synthesis that break the frame of perception and overthrow classical categories of music. We must control the internal structure of sound, by means of procedures of sound micro-surgery.’Footnote ³

Hugues Dufourt's stylistic manner may at times appear to be convoluted, but it can also be ravishing. The reader is invited to negotiate a path through philosophical passages, jumping from poetic, evocative, and vivid sentences to mere suggestions, to follow strings of references and quotations only sometimes tied down (when cited, authors are seldom referenced through specific writings), and to abandon oneself to Dufourt's erudition as well as to a prose style that often flows but can occasionally also be rather prolix.

In the end, it must be re-emphasized that the title of this book is somewhat misleading. It presents a journey through Dufourt's very personal vision in an effort to read the entire contemporary musical scene through his own ‘spectral’ spectacles. For that reason, the book should be read in terms of its emic retrospective focus (an insider's account) and very much as an individual engagement (compositional, philosophical, autobiographical, theoretical) with the broad community of spectral composers within the wider context of avant-garde music.