UFPr Arts Department
Electronic Musicological Review
Vol. 6 / March 2001

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Damián Keller


The ecological approach has provided fruitful applications in sound synthesis and composition. Its implications for the understanding of music theory, however, have not been fully explored. This article investigates theoretical aspects behind the development of ecologically-based composition. Starting from ideas presented by Shepherd (1992), it discusses whether ecologically-based music can be studied with linguistic tools. The concepts of potentiality and actuality are situated in the field of individual/environment interactions. The “personal environment” — a process describing the relationship between an individual and his specific social milieu — is proposed. Consistency is discussed in the context of environmental sound listening processes and ecological modeling work. The creation of form is dynamically determined by a process of mutual adaptation between listener and environment.


  1. Introduction
  2. Music as cultural... text?
  3. Social context and music: structural interactions
  4. Universals?
  5. Structural coupling
  6. Consistency: relaxing optimality
  7. Ecological models
  8. Summary
  9. References


Sound examples


1. Introduction

Ecologically-based compositional processes resort to familiar sound classes and temporal grouping mechanisms to provide cues that reference the listener’s quotidian sonic experience. Social references provide pointers to the cultural context where the piece belongs. Such compositional strategies do not fit the context of traditional theoretical categories. Concepts that stem from pitch-based and tonal music can hardly be applied to context-dependent and listener-specific dynamical processes. Abstract, universal laws lose meaning when musical organization relies on particular social contexts. Thus, a theoretical framework that operates from the level of micro-sonic configurations up to the level of socio-cultural relationships is needed for the implementation of ecologically-based compositions.

Performance, improvisation, aesthetics, neural processing and documentation in its several forms are all relevant to and closely connected with the present study. However, I shall tackle herein exclusively social context as related to music composition with ecologically-based sound models. The first two sections discuss two aspects of the framework: temporal levels of compositional and analytical work; socio-cultural context in its relations to sound structure. The third section addresses problems presented by the use of broad generalizations in music theory, propounding the “personal environment” as a specific dynamic process. The fourth and fifth sections deal with two fundamental concepts of ecologically-based work: structural coupling as a way of establishing potential and actual meanings between individual and environment; consistency as a means of defining sound-model constraints. The last section outlines salient characteristics of ecological models. The article concludes with a summary of theoretical points.

In accordance with the choice of the object of study, Shepherd (1992) establishes two perspectives in musicological and theoretical music research: cultural context, or the social circumstances that surround the creation and appreciation of music, and cultural text, or the sounds of music as carriers of social and cultural messages. The next section will tackle the cultural text, with particular reference to the theoretical shortcomings of syntax-based or linguistically oriented music analysis.

2. Music as cultural... text?

By introducing actual sounds as a valid object of research, Shepherd’s work departs from traditional musicological methods, which deal with everything but the music itself (cf. Leppert and McClary 1987). His use of the word “text” to designate musical phenomena is debatable though. It carries the implication that music is in some way equivalent to language and thus can be analyzed with the same tools, that is, with linguistic, semiological or syntactical tools (Lerdahl and Jackendoff 1983). [*] Syntax-based analysis suggests that music is shaped by abstract relationships which are not dependent on the dynamics of sonic processes. Only with difficulty can compositional strategies that use spectro-temporal configurations as their basic material be analyzed with such tools. Although Shepherd acknowledges the existence of musical sounds that do not lend themselves to syntax-based analysis, he keeps an explicit differentiation between sound structure and meaning in music.

According to Shepherd (1992: 136), meaning is conveyed by musical syntax, “the abstract relationships between sonic events”. Similarly to Boulez (1992) and other theorists, Shepherd asserts that these relationships have existence “primarily through the parameter of pitch, and to a lesser extent, through the parameter of duration”. The interaction between musical parameters has been discussed and experimentally demonstrated by Tróccoli and Keller (1996). The listener’s musical experience is not defined by out-of-time orthogonal variables such as pitch represented on a staff but, instead, by the interaction of concurrent processes that take place during an actual listening experience (Melara and Marks 1990). These processes do not occur exclusively at the level of syntactical events (musical notes). They also take place at the micro (timbre) and macro (musical morphology) levels (Keller and Silva 1995). To analyze music syntax through out-of-time notation is to create an object of study that does not correspond to any actual experience of music.

Further support to the idea that music-listening processes are not syntactically based follows from studies in sound identification and linguistic labeling. The experimental hypothesis goes along the following lines. If sounds are organized by means of linguistic mechanisms, then a two-stage process is required. Before cognitive relationships between stimuli can be established, one needs to assign linguistic labels to each of them. Thus, experiments would have to test whether identification processes such as labeling take place when one listens to music. A further test would have to show the difference between the mechanisms of identification and recognition.

Handel (1995) refers to a paradoxical study by Eustache, Lechevalier, Viader and Lambert (1990), in which a subject with a “left temporoparietal lesion was unable to identify common tunes but was able to discriminate whether two tunes were the same in terms of one false note, rhythm, or tempo. [...] [By contrast], another subject with a right frontal lesion could identify environmental sounds and familiar tunes, but was unable to say whether two sounds or tunes were the same”. These results indicate that identification tasks, involving labeling and speech-based cognitive mechanisms, should be clearly differentiated from discrimination tasks, which are not employed in the comparison of auditory stimuli.

Warren (1993: 40) resorts to the task of ordering acoustic sequences to verify whether labeling mechanisms are used in organizing acoustic stimuli. The stimuli consisted of groups of looped sounds. When subjects had to identify the order of the sounds presented, reaction times fell between one hundred and two hundred milliseconds. On the other hand, when subjects were asked to discriminate between different orderings of sounds, minimum thresholds dropped to from five to ten milliseconds. Warren argues that, at fast rates, subjects rely on holistic strategies to order sounds. He outlines two possible mechanisms for recognition of acoustic sequences: holistic pattern recognition, in which “temporal compounds” are not resolved into an ordered sequence of elements; identification of components, which involves the application of linguistic skills in the labeling of items. These results suggest that the micro-temporal sound structures in the range of a few milliseconds that characterize environmental sounds are usually processed by pre-linguistic mechanisms. Warren (1993: 62) surveys various studies which show that other mammals, likewise, use holistic mechanisms to group sounds. He hypothesizes that our “use of speech and production and enjoyment of music might be based upon an elaboration of global organizational skills possessed by our pre-linguistic ancestors”. In other words, music listening is probably based on spectro-temporal cues and does not necessarily rely on linguistic constructs (Figure I).

Figure I. Linguistic versus pre-linguistic mechanisms in music listening.

If compositional strategies are to be perceptually grounded, we have to move away from syntax-based methodologies to forms of sonic organization that deal with the micro, the meso and the macro levels at once. Because environmental sounds are characterized by highly varying micro and meso-temporal structures (Keller 1999a, Keller and Truax 1998), syntax-based analysis fails to deal effectively with their underlying organizational processes. Given that most perceptually relevant processes take place at a pre-linguistic level, linguistic approaches are inappropriate whenever one wishes to understand their dynamics or elaborate them in compositions. An alternative is to employ compositional models based on the sonic and referential material used in the piece. This is the perspective adopted by soundscape (Truax 1996) and ecologically-based composition (Keller 1999b). The next section discusses interactions between social context and musical structure, placing form-creation processes in the realm of social and perceptual dynamics.

3. Social context and music: structural interactions

Although Shepherd (1992) supports the view that compositional processes should make use of extra-musical references, his concepts are not entirely consistent with an environment-based approach. “[Unlike] the sounds of language, sounds in music never refer directly to people, events and objects in the external world. They either copy or evoke symbolically the sonic manifestations of those people, events and objects. Secondly, sounds in music seem not to function in a fundamentally arbitrary fashion. They function in a structural fashion that allows them to evoke, directly and powerfully, the logics and structures of the socially mediated inner life” (Shepherd 1992: 142). Shepherd is referring to syntactical structure and not to the spectro-temporal dynamics of sound. The distinction between direct reference, as provided by environmental sounds, and indirect reference, as provided by what he calls musical sounds, is illuminating and clearly reflects the view held by most theorists of music and culture regarding what elements of sound are “musical”.

Shepherd (1992) identifies three main analytical perspectives so far as cultural context of music is concerned: autonomy, structural homology and relative autonomy. The focus of each of these approaches can easily be represented in terms of how social structure influences musical structure and vice-versa (Figure II).

Figure II. Interactions between social and musical structures.

Most European and North American (ENA) music theorists believe that musical structure and meaning bear no direct relation to the social context in which music is created (cf. Bent 1987, Boulez 1992). In the analysis of stylistic features of a specific musical period (e.g., the sonata form in Classicism), they usually explain changes in compositional techniques in terms of purely structural criteria, seldom assigning extra-musical causes to them. This stance is not confined to music theory but permeates other areas of music research as well (cf. Krumhansl 1990, Parncutt 1989, Sloboda 1985). In the field of music psychology, McAdams (1987: 13) sustains that music is an autonomous phenomenon. “Music creates a non-referential (or perhaps self-referential) world. [...] It does so through psychological dimensions that are unique to music. [...] Despite its lack of specific reference it can have deep emotional significance”.

At the other end of the conceptual spectrum, structural homology provides an alternative to analytical practices that lack grounding on social content. Arnold Hauser (1951) maintains that the notion of an autonomous art is inextricably linked to capitalist socio-economic structures. The conception of an independent artist as opposed to a craftsperson depends on the dissolution of the direct bond between artist and patron. This bond is replaced by a dependency on dealers, critics, art institutions etc., which act as mediators between art producers and the consumer market (Leppert and McClary 1987). In other words, music re-produces the structure of the society in which it is being produced. Thus, musical meaning is directly linked to the social structure upon which it rests.

Shepherd’s (1992: 137) concept of relative autonomy establishes a compromise between autonomy and structural homology, striking a balance between social determinism and musical independence from social dynamics. “[...] The significance of musical sociality does not necessarily originate outside ‘musical processes’. However, musical sociality would be of little significance if its internal logics and structures were of no relevance to the logics and structures of other, non-musical social processes [...]. No artistic or cultural forms need depend on non-artistic or non-cultural social processes for their significance. [...] An ‘autonomous’ musical sociality (that is, ‘autonomous’ musical processes as social processes) may be thought of as resonating, either harmoniously or dissonantly, with other areas of non-musical sociality”. In other words, music gives life to conflicts taking place in society, but it does not literally follow the dynamics of social interactions.

Although not agreeing with Shepherd’s use of relative autonomy in support of the mythic “expression” (Stambaugh 1989: 143), “creativity” and “individuality” of the composer, I believe his position has interesting theoretical implications. Since “[music] offers up potentials and possibilities for the construction and investment of meaning on the part of people” [italics his], these possibilities can only be realized in the act of listening (Shepherd 1992). Now, listening implies enacting social and cultural processes that are ingrained in both the piece of music and the listener’s sonic experience.

Ecological psychology researchers such as Michaels and Carello (1981: 44) have drawn a line between cultural and “natural” environments. However, if we accept the idea that the musical environment is listener specific, then a single concept — the “personal environment” — can encompass the multiplicity of contexts that are brought into play when we listen to music. This environment places the work within the listener’s cultural context, re-enacting previous sonic experiences. Thus, instead of forcing sound and its organization into abstract “universal” molds, we can use the listener’s particular background to interpret the work from a specific cultural and natural context. Under this light, there is no culturally neutral listening experience. Every music carries the cultural baggage of its social origin and listeners always place the music in their personal environments. The clash between the two contexts informs the creation of musical meanings and, at the same time, reshapes the personal environment. In this manner, an ever-changing history of meanings establishes itself.

4. Universals?

ENA music theory usually treats the musical work as an object separated from actual performance, specific acoustic space, social context and reproduction mechanism, whether this mechanism is human or mechanical (cf. Bent 1987, Boulez 1992, Dempster and Brown 1990). Presenting the conclusions of her Cognitive Foundations of Musical Pitch, Krumhansl (1990: 281) states that “the investigations focused on pitch structure, and tonality in particular. This focus on tonality was chosen for several reasons. First, it plays a central role in theoretical treatments in Western tonal-harmonic music. Second, most music cross-culturally and historically can be described as tonal in a general sense that pitch materials are centered around one or a few significant tones” [italics mine]. This definition of music implies a clear hierarchy, where pitch and tonality occupy the center of the theoretical and methodological preoccupations, leaving aside such fundamental parameters as temporal organization, timbre configuration and referential elements. Another example of the “universality fallacy” in music research is found in McAdams (1987). Following Sloboda (1985), McAdams (1987: 12) draws attention to some assumptions that underlie current paradigms in music psychology, two of which tinge today’s research: the internal representation of music has a hierarchical component; scales, meter and rhythm are psychologically real organizing principles and instantiations of music universals that may be found in almost any musical culture. I suspect that McAdams is being faithful to Sloboda, since, throughout his text, he maintains that musical representations are culturally specific, while maintaining that they are simply instances of abstract universals.

McAdams (1987: 13) subscribes to the traditionally accepted view of an autonomous music. In other words, music creates meanings without establishing links with the social or natural environment where it is played. He says that “music creates a non-referential (or perhaps a self-referential) world” and criticizes the use of referential elements in music because they hinder the structural coherence. “One of the problems with musique concrète is that the sound elements [...] have such strong references to everyday life that they are made to cohere with an overriding structure only with great difficulty. [...] In a sense, the material is not only too identifiable but is also too discontinuous or categorized to be assimilable into a form that is foreign to its already strong semantic function” (McAdams 1987: 55). Correct as his assessment of concrete music may be, it is now clear that structural weaknesses in concrete music do not follow from the elements themselves but from the transformations — or lack thereof — imposed upon the material (cf. Palombini 1998, Schaeffer 1993). The “empty space” lies in the development of transformational techniques that do not destroy the referential elements of the recorded sound material. This technical insufficiency points to a conceptual shift from sound organizations established by formal processes to sound organizations framed by environmental constraints, which is precisely the niche of ecologically-based composition.

5. Structural coupling

Shepherd’s distinction between potential meanings afforded by sound structure and actual meanings realized through the act of listening finds an interesting parallel in the concept of “evolution by drift” propounded by Varela, Thompson and Rosch (1989). The theoretical biologist Francisco Varela suggests that animal and environment are mutually determined. Evolution and cognition are shaped by actual interactions between individual and environment. Differently from the cognitive approach, “cognition is no longer seen as problem solving on the basis of representations; instead, cognition in its most encompassing sense consists in the enactment or bringing forth of a world by a viable history of structural coupling” (Varela, Thompson and Rosch 1989: 205).

The idea that differentiates Varela’s (1989: 196) approach from neo-Darwinian adaptationism is the shift from optimal adaptation to “satisficing” fitness. Varela (1989: 194) states that “[t]he constraints of survival and reproduction are far too weak to provide an account of how structures develop and change. Accordingly, no optimal fitness scheme apparently suffices to explain evolutionary processes”. Patterns of animal communication are a case of varied solutions to a single problem. The use of selective frequency ranges, distinctive time-patterns or even fast-varying timbral changes are alternative approaches to sound-streaming in a noisy environment. A particularly problematic issue is the distinctiveness of signals among bird species that compete for the same niche in a shared sound environment. Time-sharing between and within species is one of the strategies employed to reduce the temporal overlap among signal emissions (Nelson and Marler 1990). Another example of selective adaptation to environmental characteristics is “the high-pitched, narrow-band, whistled alarm calls used by animals in extreme danger [...]. Due to attenuation, the high frequency signal is limited to a small surrounding space. This signal might be audible to companions close by, but will probably not be heard by the predator” (Nelson and Marler 1990: 444).

A complementary aspect of evolution by drift is the mutual determination between the individual and its environment, also called structural coupling (Figure III). “[L]iving beings and their environments stand in relation to each other through mutual specification or codetermination. [...] Environmental regularities are not external features that have been internalized, as representationism and adaptationism both assume. Environmental regularities are the result of a cojoint history, a congruence that unfolds from a long history of codetermination. [...] The organism is both the subject and the object of evolution” (Varela, Thompson and Rosch 1989: 198). Again, a specific example of information transmission in ambient acoustics is provided by Nelson and Marler (1990: 445): “Far from being a random phenomenon, the background against which animal signals must be detected and discriminated is often highly structured. It may even interact with the behavior of the signaler. [...] Thus the sound environment in which an animal species has evolved has a strong influence in shaping the acoustic signals employed for purposes of social communication”.

The separation between environment and individual in the formation of cognitive structures is arguably a severe limitation of cognitive approaches. “[P]erception consists in perceptually guided action and cognitive structures emerge from the recurrent sensorimotor patterns that enable action to be perceptually guided. [...] Cognition is not representation but embodied action. [...] The world that we cognize is not pre-given but enacted through our history of structural coupling” (Varela, Thompson and Rosch 1989: 200). It is not a mental representation that determines the formation of perceptual processes but the bodily interaction between individual and environment. A good example in the musical realm is Smalley’s (1993) assertion that instrumental gesture is a refinement of our daily interaction with objects in the environment. “The passage from object experimentation to the creation of a musical instrument involves the increasing refinement of hitting, scraping, or blowing [...]” (Smalley 1993: 537). Interestingly, sounds highly significant for survival such as the sounds of breaking, spilling and avalanches have been left out of instrumental practices.

The next logical step in the enactive perspective is to “recast selective pressures as broad constraints to be satisfied” (Varela, Thompson and Rosch 1989: 198), thus allowing for the occurrence of patterns that are not necessarily determined by selection. A metaphor for this conception is “evolution as bricolage, the putting together of parts and items in complicated arrays, not because they fulfil some ideal design but simply because they are possible” (Varela, Thompson and Rosch 1989: 196). More specifically, “form emerges in successive interaction. Far from being imposed on matter by some agent, it is a function of the reactivity of matter at many hierarchical levels, and of the responsiveness of those interactions to each other. [...] [The] extraorganismal environment is made internal by psychological or biochemical assimilation. [An] internal state is externalized through products and behaviors that select and organize the surrounding world” (Oyama 1985 cited in Varela, Thompson and Rosch 1989: 199). This thesis is consistent with an ecologically-based theoretical framework insofar as musical structures provide potential meanings that are realized through a mutual determination process between individual and environment. Significantly, hierarchical descriptions of sonic processes from a structural perspective are generally absent from the literature (Keller and Silva 1995).

Figure III. Structural coupling between individual and environment generates a pattern formation process.


6. Consistency: relaxing optimality

As the previous section demonstrates, current evolutionary theories view natural selection as the realization of possible outcomes, rather than as a result of necessity. In other words, we “recast selective pressures as broad constraints to be satisfied” (Varela, Thompson and Rosch 1989: 198), a perspective that allows for the occurrence of patterns that are not necessarily determined by selection. Artificial Intelligence approaches, on the contrary, usually come up with a single, optimal solution in a predefined parameter space. Cooke (1993: 55) pointed out that “the questions of optimality and search are not often raised in experimental studies of auditory grouping. Instead descriptions of strategies are more common. [...] [T]his work is based on heuristics which express the belief that it is possible to discover similar groupings from large numbers of different starting points”.

The adaptability of perceptual processes places two requirements on the implementation of perceptual and compositional models: the same mechanisms must be usable for different stimuli in different contexts; several perceptual states must be obtainable from a single stimulus. The first requirement may be inferred from the precedence effect: regardless of the source sound, the perceptual system separates source from ambience reflections. The second requirement is exemplified by the repeating stimuli used by Warren (1993). They are perceived as changing even when no physical change occurs.

Ellis (1996: 54) proposes more flexible criteria for a better match between model and data in auditory processing. A data-driven model such as Cooke’s constructs successive levels of abstraction founded on identifiable features of the data. On the other hand, “in the prediction-driven framework, the model itself is obtained by drawing predictions from the existing components, and the ‘connection’ is limited to ensuring that the model falls somewhere in the space of uncertainty. Depending on how model and stimulus uncertainty are represented, there may be a wide range of possible matches, with a continuum of resulting confidence or quality metrics, rather than a single, brittle yes/no comparison”.

Thus, work carried out in computational auditory modeling coincides with the theoretical approach proposed in evolutionary biology: perceptual mechanisms are constrained by environmental requirements, but no single optimal solution exists for a given state in the process of individual/environment interaction. Transposing these principles to the compositional domain, one will seek to implement sound models that provide environmentally consistent sonic cues. Consistency in this context can be defined as the relationship between dynamically varying sonic cues, in compliance with the characteristics of the environment and the states of the source object. These constraints provide a basic framework for the development of ecological models shaped after the properties of everyday sounds. Some of the most relevant among such properties may be formulated as follows: the minimum temporal unit is the ecologically meaningful sound event; no event happens twice, that is, spectral and temporal characteristics change continually; the object/event relation is constrained by the possibilities of the object, that is, a given object can only produce a limited range of spectro-temporal behaviors. By following these premises, researchers secure that the output of the synthesis model remains within a particular sound class and, at the same time, avoid a one-to-one correspondence between the model and the sounds obtained. In other words, as long as the parameters of the sound model are kept within ecologically valid ranges, each instantiation will belong to the same class but no two instances will be alike (Figure IV).

Figure IV. Comparison between formal closed systems and structural coupling as a pattern formation process.


7. Ecological models

Through research into environmental sounds (see Keller 1999a) I have been led to conclude that the development of compositional tools must be a function of ecologically meaningful events and of sound classes and sound behaviors consistent with the possibilities of objects. In ecological modeling, variables are directly related to environmental processes such as excitation of resonant bodies, time patterns etc. The range of possible values that these variables can take is restricted to ecologically feasible spans. Thus, a ball cannot bounce forever and a surface cannot be perfectly regular. These sounds provide cues to feasible events in the environment. By doing so, they engender stimuli that are coherent with pattern-formation processes (cf. Sound Examples). If mutual determination is a reasonable model, we should expect to find fine-tuned perceptual mechanisms to process frequently occurring environmental sounds (Figure V).

Figure V. The multiple temporal layers and their relationship with the personal environment.


8. Summary

Ecologically-based musical approaches need to be grounded on the specific social environment where the musical work is placed, taking into account the dynamics of sound structures and the listening processes. Universal concepts proposed by ENA music theory and cultural studies such as “neutral cross-culturalism”, “Western culture” and the like are not capable of dealing with the dynamics of specific social and perceptual processes. They overlook important aspects of musical organization such as referential elements and mutual adaptation processes. Because ecologically-based sounds are characterized by highly varying micro and meso temporal structures (Keller 1999b, Keller and Truax 1998), syntax-based analysis fails to deal effectively with their underlying organizational processes. In addition, most perceptually relevant processes take place at a pre-linguistic level.

A separation between musical sound and environmental sound can only be made in relation to a specific artwork in a given cultural context. It makes no sense as a general or “a priori” statement. Truax (1996) argues that it is the ability to make direct references that turns environmental sounds into ideal raw material for composition. These sounds offer the possibility of creating meaningful symbolic systems by evoking the listener’s sonic environment. A new layer of meanings is thus established, where the listener’s cultural context interacts with the dynamics of sonic structures. To embrace the model of mutual determination in its entirety means to accept the idea that music is realized during the listening. This perspective places the concepts of potentiality and actuality in musical meaning within the broader realm of mutual determination between individual and environment. In this context, the interaction between the specific sonic experiences of the individual and the structural processes of the music sets in motion a process of form creation that brings forth an ever-changing history of meanings.

9. References

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KELLER, D. and SILVA, C. 1995. “Theoretical Outline of a Hybrid Musical System”. Proceedings of the Second Brazilian Symposium on Computer Music. Canela: Sociedade Brasileira de Computação. Pp. 248–57.

KELLER, D. and TRUAX, B. 1998. “Ecologically-based Granular Synthesis”. Proceedings of the International Computer Music Conference. Michigan, Ill.: International Computer Music Association. Online at <http://www.sfu.ca/~dkeller>.

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NELSON, D. A. and MARLER, P. 1990. “The Perception of Birdsong and an Ecological Concept of Signal Space”. In W. C. Stebbins and M. A. Berkley (Eds.). Comparative Perception II. New York: John Wiley.

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PALOMBINI, C. 1998. “Pierre Schaeffer, 1953: Towards an Experimental Music”. Electronic Musicological Review 3, <http://www.humanas.ufpr.br/rem/REMv3.1/vol3/Schaefferi.html>.

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SHEPHERD, J. 1992. “Music as Cultural Text”. In J. Paynter, T. Howell, R. Orton and P. Seymour (Eds.). Companion to Contemporary Musical Thought I. New York: Routledge. Pp. 128–55.

SLOBODA, J. A. 1985. The Musical Mind: The Cognitive Psychology of Music. New York: Oxford University Press.

SMALLEY, D. 1993. “Defining Transformations”. Interface 22: 279–300.

STAMBAUGH, J. 1989. “Expressive Autonomy in Music”. In F. J. Smith (Ed.). Understanding the Musical Experience. Montreaux: Gordon and Breach Science.

TRÓCCOLI, B. T. and KELLER, D. 1996. “A função da familiaridade no reconhecimento do timbre”. Technical Report. Brasília: FAP-DF.

TRUAX, B. 1996. “Soundscape, Acoustic Communication and Environmental Sound Composition”. Contemporary Music Review 15 (1): 47–63.

VARELA, F. J., THOMPSON, E. and ROSCH, E. 1989. The Embodied Mind: Cognitive Science and Human Experience. Cambridge, Mass.: MIT Press.

WARREN, R. M. 1993. “Perception of Acoustic Sequences: Global Integration Versus Temporal Resolution”. In S. McAdams and E. Bigand (Eds.). Thinking in Sound. Oxford: Oxford University Press. Pp. 37–68.

Damián Keller, DMA candidate, MFA
Center for Computer Research in Music and Acoustics
Stanford University
CA 94305, USA

Ecological Models


Editor’s Note

[*] Semiology/Semiotics took the notion of “Text” beyond Linguistic borders in 1974. See Roland Barthes’s “L’aventure sémiologique”, in Le Monde of 7 June 1974, reprinted in L’aventure sémiologique, Paris, Seuil, 1985, pp. 9–14, translated into English as “The Semiological Adventure”, The Semiotic Challenge, Oxford, Blackwell, 1988, pp. 3–8.