Page  213 ï~~The Morpho Concepts " trends in software for Acousmatic Music composition Daniel Teruggi Groupe de Recherches Musicales - INA 116 Av du President Kennedy - 75786 Paris Cedex 16, FRANCE INA.GRM @a Abstract Since the origins of the musique concrete, the search of a new musical expresion has been associated with a research on new means of manipulating sound phenomena. For the last 20 years, the GRM has developped a number of computer applications, used by dozens of composers, including the SYTER system and more recently, GRM Tools, MIDI Formers, and the Acousmograph. Although these applications were developped in different contexts and by different people, they refer to a common approach to sound perception and to sound manipulation, and they share a number of concepts that have proved efficient in practical creative situations. The problem being what parametra to control and how to do it. This paper is a first attempt to analyze these common concepts. It will be based on examples realized with GRM Tools, with the MIDI formers and the Acousmographe. With the first experiences of "musique concrete" in the fifties, new conceptual and technical needs appeared necessary for dealing with the particular situation proposed by sounds deprived of their original phenomenological context. During this first period were sketched intuitively the principal ideas and techniques that would orient the subsequent generations. The principal axis of research consisted in developping more adapted technical and theoretical tools to permit further musical achievements and to understand the esthetical implications of this new sonic art in which instrumental performance was replaced by the coherent articulation of any listenable sound source. Historically the first Morpho Concept was that of observation itself or, as Pierre Schaeffer called it, the "reduced listening" in which new observation conditions (as those produced by listening to sounds independently from their original context) produce new listening phenomena, and the further situation in which sound becomes an object ("sound-object") and can be transformed into a musical-object by manipulation and integration into a new context, a purely musical context.[Schaeffer, 1966] A certain number of Morpho Concepts followed this first one; some of them, depending on the available techniques: cutting, sound-inverting, speed-variations and loops, dealed with profound modifications of the time axis and the isolation of this parameter from its unidirectional flowing thermodynamical consequence. Filtering permitted spectral modification on sound-objects or the isolation of some kind of phenomena within complex sounds. Spatialization introduced a new concept in which space and time-perception intimately react, and the three-dimensional presence of sounds gave space a unique and new musical value. New Morpho Concepts appeared later, musical experimentation and technical achievements enlarging the scope and directing new research projects. Very soon, new tools were needed capable of manipulating sound parameters in a more precise and oriented direction: the "phonogene a coulisse", the "phonogene chromatique" and the "morphophone" were mechanical devices that permitted continuous or step by step sound transposition as well as sound fragmentation and sound prolongation (a mechanical sampler in a certain way). These devices constructed in the fifties implied the possibility of having a precise and varied control on time as a parameter, in order to explore the morphological patterns of sound. In 1972 the term "musique acousmatique" was reintroduced by Franqois Bayle in order to describe the music made with electroacoustic or computer means and using tape or other kinds of magnetic and optical means as its final support. Acousmatic music may associate performing instruments but treated from a Morpho Conceptual approach. From an esthetical point of view acousmatic music concentrates on the poetical and spectral richness of sounds and plays with this very ICMC Proceedings 1994 213 Composition, Composition Systems

Page  214 ï~~particular characteristic of sound hearing in which the perception of an acoustic phenomena is associated with its cause; hence the perception of a sound whose cause is unknown or unrecognizable for our perception, induces the listener to imagine unexisting causes and to percieve music as a complex creative phenomena in which musical sense and musical sounds have to be interpreted simultaneously, with generally very little relation with our perceptive reality. The question is not to find out how sounds are made but how their combination will generate imaginary perceptions of imaginary realities in our mind. [Bayle, 19933, [Teruggi,1993] The arrival of digital technology opened a new age for Morpho Concepts, a more accurate control on sound parameters was possible, and new sound manipulations were imagined. The first software achievement began in 1975 with a package of non real-time programs (called the 123 programs). The primary aim of these programs was to simulate the analog studio facilities as well as the obsolete "phonogene" devices. Very quickly enormous new possibilites for sound transformation were developped and the basis for Morpho Concepts in the digital era were established. Several Morpho Conceptual categories can be presented proposing a large variety of tools for sound exploration. These are general categories, complex manipulation may act on several categories simultaneously; time axis modifications: time-stretching, time-contracting, time-freezing, time-reversing spectral modifications: filtering, resonant filtering, harmonizing, ringmodulating time-pitch modifications: time-delays, speed-variations, doppler effect density modifications: event accumulation, complex feed-backs, multiplication order of events modifications: sound fragmentation, sound shuffling, silence incrusting spatial modifications: doppler effect, complex panning, spatialposition simulations, reverberations Non real-time calculations permitted an extremely precise control on sound but distanced the user from the inmediate sound experience which has always been a fundamental characteristic in acousmatic composition; therefore very soon a real-time project was developped under the name of S YT ER. This real-time sound processor oriented towards sound tranformation and sound synthesis, working on a PDP 11/23 system, permitted a very quick and ergonomic approach for sound manipulation on Morpho Conceptual basis. Almost all of the non real-time software were transferred to this system permitting an excellent interaction with the user.[Allouis,1984] The next step was to adapt this software to personal hardware, and with a Sound Tools support, a new generation of software was developped under the name of GRM Tools. In this software old and new Morpho Conceptual algorithms were adapted to this largely diffused card. The software joins a powerful sound modification tool with a very ergonomic graphic interface in order to achieve quick control and modification on sound processes. Each algorithm of GRM Tools develops one of the conceptual categories described above permitting advanced sound transformations in a Macintosh environment. [Vinet, 1991] The second package of Morpho Concept tools, came through MIDI systems and MAX software with the name of MIDI Formers (formerly called MacSoutiLs). MIDI code is more oriented towards instrumental action than to acousmatic work, so the general idea was to develop patches capable of generating large amounts of MIDI events when recieving a trigger command. These events are organized according to Morpho Conceptual behaviour models such as: bouncing, fortune-wheel, granulation, glissandi, repetitions and random control. These models represent the basic actions for which each patch is concieved, numerous and varied modifications permit a global control on all MIDI parameters intervening within the patch by means of a graphic interface with sliders, memories and switches modifying the flow of events to obtain very complex situations. [de Laubier, Teruggi, 1991] The third Morpho Concept tool is the Acousmographe that is a graphic tool for acousmatic score drawing based on a sonograph. This software creates very accurate sonograms and bathygrams of any music thus obtaining a description of spectra and amplitude in function of time. With these two scientific descriptions of a music or a sound phenomenon, the user can place on the graphic frame any kind of symbol extracted form a very large library of graphical and traditional symbols and then adapt Composition, Composition Systems 214 ICMC Proceedings 1994

Page  215 ï~~these symbols (or else create new ones) to the sonogram in order to represent sound events as they are percieved and not only as sound spectral descriptions. The result is an "aural score" of a music, in which listening can be coupled to a graphic support that may contain a purely scientific description of the music, a traditional instrumental score or a morphological description of our muscial perception. The Acousmographe provides a useful tool for musical analysis and concert performance oriented towards non notable music.[Koechlin,Vinet, 1991] These three developments: GRM Tools, MIDI Formers and the Acousmographe, are the essential tools for the Morpho Concepts, which represent the basis for acousmatic composition. Their existence has been confirmed by over 1400 musical works composed in the G R M studios since 1948. These works are a result of a close interaction between development teams and composers who have always proposed morphological concepts that were then implemented by analog or digital means. In the last years a large acousmatic library called Acousmatheque has been established to preserve, restore an permit research and diffusion of the music produced inside and outside the GRM as well as all the writings and scores concerning acousmatic music. An important CD collection permits a large spread of GRM music with 30 CD's issued already. The final link of the Morpho Concept chain is the Acousmonium or loud-speaker orchestra composed of 70 loud-speakers of different forms and dimensions specialized for acousmatic music. This system permits music to live in its final communication space; the concert hall in which performed sound projection permits listening to be the perception of an intentional act related to a place, a performer and a public and, not a simple sound diffusion situation. in Acusmatic Music, essential for the morphodynamical approach to sound structures. References [Schaeffer,1966] Pierre Schaeffer, Traitd des objets musicaux, Le seuil, Paris, 1966 [Bayle,1993]Francois Bayle, Musique Acousmatique, propositions...positions, INA GRM - Buchet Chastel, Paris, 1993 [Teruggi,1993]Daniel Teruggi, What about Acousmatics, Journal of Electroacoustic Music, Sonic Arts Network, London, 1993. [Allouis,1984]Jean-Francois Allouis, Logiciels pour le systeme temps rel SYTER, ICMC proceedings, Paris, 1984. [Vinet et al., 1991]Hugues Vinet, Olivier Koechlin and Didier Brisson. DSP Station, a HyperCard environment for DSP sound processing algorithms, ICMC Proceedings, Montreal 1991. [de Laubier, Teruggi,1991]Serge de Laubier, Daniel Teruggi. MIDI generation of sound morphologies, ICMC Proceedings, Montreal, 1991. [Koechlin,Vinet, 199 1]Olivier Koechlin, Hugues Vinet. The Acousmographe, a Macintosh software for the graphical representation of sounds.ICMC Proceedings, Montreal, 1991. Conclusion The Morpho Concepts are the principal trends of Acousmatic music. Their appearence 40 years ago has influenced the musical works and the esthetical approach of several generations of composers since.Their continuity through time is a proof of their conceptual value on which software development has been articulated since 1972. They have also permitted a close relationship between technical research and practical music application, offering a coherent ensemble of tools for composition, analyse and sound phenomena control. This paper is a first attempt to integrate in a coherent esthetical frame, the whole of the tools and concepts used ICMC Proceedings 1994 215 Composition, Composition Systems