Page  00000515 Morphopoiesis: An Analytical Model for Electroacoustic Music Panayiotis A. KOKORAS Department of Music Studies, School of Fine Arts, Aristotle University of Thessaloniki Abstract The use of sonic attributes as a form-bearing dimension has undoubtedly opened up new possibilities for the composer. At the same time this new content has raised the question of what is the procedure of structuring form by means of timbre. On the basis that timbre can be a main form-bearing element and that content is strongly related to form, then this new content must suggest a new form as well. However, there is no past reference, at least in western music, to describe such a procedure. This paper provides a basis that aims to identify and clarify an analytical model capable of giving an exegesis about the relationship between content and form. It also offers an analysis of the primary principles on which the potential new musical form is built. It studies the organizing principles of the internal attributes of a musical work that give a unit its specific identity, the functional relationships between it and other units, and the ordering and direction of those units. 1 Introduction Although it is evident that music takes place in time, it has always been a compositional issue about how form unfolds in time. The word form itself can sometimes cause confusion by referring either to a generic type - the overall structure of a composition such as symphony or mass, or to procedures that define how sound units are put together to make phrases and sections. This paper focuses on the latter procedures, on form-creating devices in which small bits of material are treated to many different presentations and combinations [DeLone 1975]. It examines structural processes that determine all the note-to-note - or better, sound-to-sound - details. For centuries, the main form-bearing musical elements were melody, harmony and duration. From the way these musical elements are used, an experienced listener can easily identify the century in which a composition was written, even the composer by whom it was written. During the last few decades, however, a new dimension has begun to emerge as a form-bearing element, that of timbre [McAdams 1983]. The use of timbre as a form carrier may suggest a new content, a primary material ready to be shaped and to acquire form. The concept of form as unified with content constitutes a key to the better understanding of musical organization. As Edgar Varese has said, "Form and content are one. If there is no form, there is no content, and if there is no content there is only a rearrangement of musical patterns, but no form" [Varese 1936]. The new relationship between timbre and form does, however, bring to the fore some questions. How can timbre be a formbearing element? What are the procedures that empower it with such attributes? What sort of process should it be run through? How is it connected with musical form? This paper will propose an analytical model for structuring form, a process that could encompass a great deal of electroacoustic music as well as a great deal of the mixed, instrumental and vocal works of recent decades. 2 Morphopoiesis as a Model In an effort to define more precisely a framework for a systematic form-creating device, this paper introduces the term Morphopoiesis. It is proposed to give a rather specific and descriptive process paradigm of structuring musical form that derives from the interaction between content and form. Morphopoiesis offers an abstraction of the primary principles by which a new musical form is built up. It focuses on the procedures of the inner formal characteristics of a musical work which give to a sound its specific identity, the functional relations between it and other sounds, and the motion and direction of those sounds. It is an analytical tool for analyzing, listening to, and making music of all kinds, ranging from electroacoustic music to instrumental and vocal music. It refers to music that concentrates its interest on changes in the intrinsic and extrinsic attributes of the sound in the flux of time. This process can be more easily and effectively applied, however, in electroacoustic music where the composer, with the help of computers and specialized software, can manipulate, mix and process sound with great precision and detail. In instrumental music, the sound manipulation and control can be achieved either by the use of live electronics, where a computer can receive music as it is being performed and can process it and play it back in real time, or through fixed, pre-recorded electroacoustic sounds which are played together with the instrument(s). The etymology of the word is simple: Morphopoiesis is a composite word consisting of the prefix morpho- which means structure, shape, form (from the Greek morphe), and the suffix -poiesis which means creation, formation, 515

Page  00000516 production (from the Greek poiesis, which is formed from the verb poiein "to make") [Microsoft Encarta 2003]. The process of Morphopoiesis consists of four levels which will be further explained in section 4. 3 Form as a process It is difficult to distinguish compositional procedures, since most of them imply some transformation of the initial material with the retention of certain essential original features [DeLone 1975]. As a result, these procedures may not be entirely universal but they can be sufficiently general to give us a better understanding of the craftsmanship of musical form in each historical period. In all the structural processes of the past, the complex is created by combination of the simple, which remains discrete and unchanged in the complex unity [Chester 1970]. Every epoch in western music from the Middle Ages until the present is characterized by a general type of structural process, although not all music falls into these types. More than one formal method may be used including intermediate types in the same period. Table 1 shows the main structural processes related to their era, the musical texture that characterizes each era and a representative form. Era Texture Form Structural process Middle ages Gregorian Monophony Ca Chant Text setting Renaissance/ Canon, Baroque Polyphony Mass Sectional variation Baroque Mass Classicism. I Developmental Romanticism Homophony Sonata vanation Table 1. The structural processes according to their era This paper proposes the concept of Transformational variation as a next step to the evolution of structural process in western music for the period from 1950 to the present. It will further explained at the First Level 4.1 of Morphopoiesis. At its base, it describes the way one sonic identity is combined with another. It is a perceptible process in that a listener is able to hear the process happening throughout the performance. This becomes unavoidable, especially in electroacoustic music where a representation of the music is not always necessary for the performance. point represented by the black thick line is transformed to an even thicker texture in 'transformation a', although it keeps most of the melodic profile [Chion 1983] of the starting point. In the next stage, the spectral elements and the mass profile [Chion 1983] of the sound change more and the overall shape goes a step further away from the previous stage. Finally, in 'transformation c', the two parts of the initial idea are separated by silence and the whole morphology and spectral components of the two sounds now become even more different from the previous stages. 4 Defining structural levels A hierarchical framework of the four levels will now be introduced, from the fourth or highest to the first or lowest, with the scope to analyze the structural process of Morphopoiesis at its primary components. The categorization of the four levels of Morphopoiesis takes into consideration the research done by several theorists and practitioners in areas such as music perception and cognition by McAdams and Bregman, sound morphology and typology originally introduced by Schaeffer, and spectromorphology by Smalley. Morphopoiesis integrates these theories into a general procedure that aims to provide a better understanding of how form is structured. 4.1 First Level The first level placed at the base of the structural process of Morphopoiesis is the transformational variation. This describes the form type of the gradual change from one point to another and the sound process(es) used for it in the flux of time. Transformations can normally be applied in a point to point form. This results in several other variations, of which the simplest are that of Binary transformation - from point A to point B (AB) - as well as Ternary transformation (ABA), Arch transformation (ABCBA), and so on. In addition, transitions from point A to point B may be realized via cross-stage steps called transitional chains. As a result of this process, for a binary A to B transformation extra steps can be added in between the start point and the end point to create a transitional chain. The degree of the gradual transformations can vary from fast to very slow, from a rapid succession of gestures that changes in time to a slow textual evolution. Landy suggests that sound transformation should happen gradually within a minimum of about four seconds in order for it to be perceived by the listener [Landy 1991]. In addition, the first level of Morphopoiesis clarifies the sound process used for the transformation in its totality. That is, in addition to the independent process, the sound units themselves can undergo a general sound process which characterizes the whole transformation. In practice, however, the technique most likely to be used is that which involves more than one sound process of the same domain, and even a combination of different domains. Nevertheless, it is not always necessary for a sound transformation to be i it rai transformarion b n A0 i transformaton c nisfoirmaion a ' Figure 1. the stages separated by dotted lines are not intended to represent a 'natural' musical flow but rather to show an example of some further steps in the process. Figure 1 represents graphically the structural procedures by giving a simple example in three stages. The starting 516

Page  00000517 interwoven by a sound process too, although this is most common. Three are the main types of sound process: 1) Spectral domain - procedures for the alteration of spectral data such as spectral stretching and convolution; 2) Time domain - with techniques such as sound block displacement, time-stretching, interleaving, freezing and interruptive effects in time before certain blocks emerge; 3) Frequency domain - processes like filters which resonate or attenuate a particular area or areas of the spectrum. From the early 1970s, the composer Trevor Wishart developed a large number of procedures for sound processing almost all of which can vary through time. The Phase Vocoder is used to provide most of his spectral transformation tools such as spectral morphing, shifting, stretching, cleaning, banding, tracing, blurring etc. Wishart has said that, "the musical structure of the piece was conceived in terms of such transformations between sound types...". A more detailed documentation for all these tools can be found in his book Audible Design [Wishart 1994]. sound identities. Another process domain could be considered to be that of Context, or Space. However, the transformation realized in both of these is not directly related to timbre. In fact, the timbre remains unchanged while the aspect of context or space changes. Although the musical potential of context and space is of great interest, it is beyond the scope of this paper, since their transformational attributes are not directly related to timbre. 4.2 Second Level The second level of Morphopoiesis considers the typomorphological procedure; the specific identity of the sound material, the functional classification and relationship between it and other sound units, and the detailed description of those sounds. Once the type and process of sound transformation has been defined, the next level is required in order to study the sound material available as pure sounds without any contextual influence and to evaluate and arrange them into groups and categories. After being identified and classed, the sounds are described in great detail according to their intrinsic and extrinsic attributes. Schaeffer [Schaeffer 1966], in his description of Solfege de I'objet Sonore, proposes seven morphological criteria: mass, harmonic timbre, dynamic, grain, allure, melodic profile, and profile of mass [Chion 1983]. Under these criteria, the whole structure gets a clearer and smoother direction through unified and coherent sound identities. A proposition by Landy categorizes binary sound transformations in five ways according to the following categories, four of which are parametric and one is contextual sorted: 1) comparable... incomparable sounds, 2) discrete... continuous, 3) short... long, 4) representational... abstract, 5) same sound... different context [Landy 1991]. This categorization does, however, assume an a priori integration with level one and it does not take into account the next two levels. Another example is that of Fischman, who has provided the following seven suggestions: Differentiability, Similarity, Duration, Linearity, Spatial movement, Diversions and Context which, depending on the circumstances and the context of a composition, may help in producing convincing results of sound transformation [Landy 1991]. 4.3 Third Level The next level in ascending order attributes motion and sets stronger relationships between spectral typologies and morphologies. The definition of motion and its classification into six categories (bi-directional, uni-directional, linear, curved-linear, reciprocal and centric/cyclic) proposed by Smalley is a comprehensive guide that characterises both small units and whole phrases or sections. The energy of motion is expressed through spectral and morphological changes. When the changes refer to the internal structure of the sound, the music is primarily textural without forward motion. In music which is primarily gestural, the changes refer to the external structure of the sound driving the material forward. All degrees of combinations between texture and gesture can appear within a single composition. An in-depth examination of the motion and growth process is provided by Denis Smalley's texts [Smalley 1994]. 4.4 Fourth Level The fourth and highest level of Morphopoiesis studies the relationship between sounds and the brain's interpretation of them. Perception and cognition are deliberately placed on the highest level to enable the listener to grasp a large-scale pattern if there is one, to understand the balance between units, or to connect the primary with the secondary parts of the music. This final stage is the level that aims to integrate all the previous levels into a whole. Many recent experiments and theoretical approaches by researchers such as Stephen McAdams [McAdams 1989], Fred Lerdahl [Lerdahl 1992], Albert Bregman [Bregman 1990] and others have shown that structuring musical form itself is not enough if it cannot be understood by the listener. It informs the composer about the constraints and possibilities of the apprehension of musical form in terms of the perceptual processes and memory structures which are activated as form is accumulated in the mind of a listener. The interaction between composer and musical form depends on an understanding of both music cognition and perception. There are several examples of music, such as total serialism and aleatoric music, where the form processes and the sounding music do not always have any audible connection. Morphopoiesis is a form process that must be heard when the piece is performed. It is a systematic framework for the way we listen to and appreciate music. It is necessary if a listener is to become aware of the new 517

Page  00000518 content while distrusting preconceived ideas and relying first and foremost upon what is heard. I ces2 Leve-s a C oh -s "e age.......... h:n B?\m~g~~ Lelvel. 4,1 Sgniion" Perc41io1. Level Motion TypLev phel ogy Level 1:.I\..... Uk... the s-k-ectrurn ý Fl.4U Figure 2. The four levels of Morphopoiesis with an example of a Binary A to B transformation. The representation in Figure 2 presents this process in greater detail. It begins with Level 1 at the bottom where the two points A and B are identified and the two intermediate stages are being determined. This model can already be identified as a Binary transformation with a two-stage transitional chain. The sound process domain of the model is further clarified and its particular effect is revealed, which is a sound filtering process. This involves a continuous attenuation of particular areas of the spectrum. The sound process domain is considered to be an overall process that passes across the whole transformation. The use of the typomorphological characteristics of the sounds at the second level helps the sound material to be placed in order and classified into different types and groups according their morphological characteristics. At level 2, the corners of the square graphic representation of the sound take on a more and more rounded shape until they eventually become a circle. Concurrently, the sound filtering process is applied gradually. At level 3, the individual sonic units acquire motion; a rotating motion is achieved through spectromorphological variation. At the same time, a slow ascending motion adds direction to the rotational motion leading the listener to expect possible outcomes. Finally, at the top level, the primary sonic units lose their individual identity and contribute to a totality. The whole transformation sounds like a spinning gesture that moves upwards while its spectral density attenuates and eventually moves to the destination point. The same time, the sound qualities change from rough (square) to rather glossy (circle). It becomes a compound sound object that bears functional elements able to create expectation and tension, to create music. 5 Conclusion The concept of Morphopoiesis suggests an analytical model for structuring musical form. It studies how the smallest sound units are put together to make phrases and sections: to make music. It summarizes the work done by numerous practitioners and theorists over recent decades on the organized use of timbre and its perception. Although the knowledge and the experience acquired over all these years covers a great many of the aspects and approaches to this process, they were disparate and widely-scattered without a single unifying thread to connect the elements. I hope that the unified approach proposed in this paper can offer a systematic and in-depth tool to both theorists and composers, a tool for the better understanding and appreciation of a considerable amount of the music today. That is, music which focuses on changes to the inner and outer attributes of the sound in time. This is best represented by the majority of electroacoustic music, as well as by a number of instrumental and vocal works. References Bregman, A. 1990. Auditory Scene Analysis: The Perceptual Organization of Sound Cambridge, Massachusetts: The MIT Press. Chester, A. 1970. For A Rock Aesthetic. New Left Review 59, pp. 82-86. Chion, M. 1983. Guide des Objets Sonores. Eds. Buchet/ Chastel, Paris. DeLone, R. et al. (Eds.) 1975. Aspects of Twentieth-Century Music. Englewood Cliffs, New Jersey: Prentice-Hall. ASIN 0130493465 Landy, L. 1991. Sound transformation in Electroacoustic Music. Composers' Desktop Project Manual. York. Lerdahl, F. 1992. Cognitive Constraints on Compositional Systems. Contemporary Music Review 6 (2), pp. 97-121. Harwood Academic Publishers. McAdams, S. 1989. Psychological constrains on form-bearing dimensions in music. Contemporary Music Review. 1994, Vol. 10, Part 2, p. 35-48. Harwood Academic Publishers. McAdams, S. 1983. Spectral fusion and the creation of auditory images. Music, Mind, and Brain. The Neuropsychology of Music. M. Clynes, p280. Edition New York: Plenum Press. Microsoft Encarta Reference Library. 2003. 1993-2002 Microsoft Corporation. All rights reserved. Morris, R.O. 1935. The Structure of Music. London: Oxford University Press. Schaeffer, P. 1966. Traite des Objets Musicaux. Paris Edition du Seuil. Smalley, D. 1994. Defining Timbre - Refining Timbre. Contemporary Music Review, 1994, Vol. 10, Part 2, p. 35-48. Harwood Academic Publishers. Smalley, D. 1997. Spectromorphology: explaining sound-shapes. Organized Sound 2(2): 107-26, 1997. Cambridge University Press. Varise, E. 1936. The Liberation of Sound. Perspectives on New Music New Instruments and New Music. Wishart, T. 1994. Audible Design. Published by Orpheus the Pantomine, UK. 518