Book reviews

Perry R. Cook (ed.), Music, Cognition, and Computer- studied to inform emulation synthesis. The bulk of this ized Sound: An Introduction to Psychoacoustics. Cam- material probably would not appear in a psychoacoustics bridge, MA: MIT Press, 1999. ISBN0-26203-256-2. book that did not have a research frame. The chapters that discuss the role of tactile feedback The preface of Music, Cognition, and Computerized processes (haptics) in musical sound production and per- Sound describes the work as an introduction to psycho- ception are another distinctive aspect of the book. I par- acoustics, geared to those interested in music. Designed ticularly welcome the inclusion of this topic, with hopes to function as a textbook for independent study or for that it will bring the importance of tactile sense in courses at the college sophomore level or above, each expressive instrumental control further to the foreground of the book’s chapters provides a succinct treatment of in computer music research. a given topic. These are intended to be readily adaptable The final chapter in the book is a brief introduction to to lecture presentation or specific research needs. An designing experiments in perception, geared towards the appendix containing suggested exercises for labs and expectation that students taking a course complete a another containing questions and thought problems fur- simple experiment in psychoacoustics as a term project. ther support classroom instruction. The work is accom- Given that many students likely to be taking such a panied by a combined audio CD and CD-ROM provid- course would not be trained in this discipline, this chap- ing sound examples related to the text and source code ter seems a valuable and helpful addition. It covers the for those examples. goals of scientific research, different types of studies, The terms used in the title – music, cognition, compu- common flaws in research design, ethical issues, and terized sound and psychoacoustics – together represent statistical methods. It is clear, particularly in the latter a vast arena of potential inquiry. The scope of the book case, that the one chapter cannot truly do the topic just- can be described as the intersection of those four ice. But enough material is provided to cultivate critical domains plus specific trajectories that computer music thinking about experiment design at an introductory inquiry has taken historically, particularly at Stanford level. University’s Center for Computer Research in Music Only a few things struck me as out of place or incom- and Acoustics (CCRMA). In fact, the book finds its gen- plete. The chapter on ‘Storage and Reproduction of esis in a course offered at CCRMA since the 1980s. All Music’ discusses the encoding and reproduction of of the contributing authors – , Perry R. music. This is a topic of interest to the computer music Cook, Brent Gillespie, Daniel J. Levitin, Mathews, researcher, and it is certainly linked to issues of percep- John Pierce and Roger Shepard – have been faculty, tion. But in the form presented in the chapter – touching researchers or students at Stanford. How this prominent with only the briefest of treatments on topics such as lineage in computer music research defines the content LPC, deterministic and stochastic elements in phase voc- of the book provides an interesting point of reflection. oder analysis, and loudspeaker reproduction – it does not Within the common domain of psychoacoustics, the seem very helpful. The chapter ‘Passive Nonlinearities book covers the physiology of the ear, cognitive psycho- in Acoustics’, while potentially quite interesting, pro- logy related to hearing, the definition and metrics of vides its concrete examples primarily in terms of circuit sound, auditory scene analysis, scales and tunings in design and thereby probably precludes meaningful relationship to perception, and musical memory. understanding by people not versed in electrical engin- Beyond this, the research interests of Chowning and eering. There was an opportunity lost here to provide a Cook are represented in a relatively large volume of bridge to understanding of physical modelling in general material on the human voice, primarily on the mechanics and the role and modelling of nonlinearities in particular. of production and to a lesser degree on perceptual issues. I was pleased with the clarity of the language and This incursion into the physics of sound production is the presentation of ideas. I only identified a handful of extended with materials on vibrato and nonlinearity in sentences or paragraphs where I found the language sound production mechanisms. The appearance of these overly convoluted or explanations incomplete. As such, topics reflects a historical computer music research the book should function effectively in its intended intro- thread in which the physics of sound production is ductory textbook role at the college level. However, at

Organised Sound 5(2): 111–116  2000 Cambridge University Press. Printed in the United Kingdom. 112 Book reviews

times assumptions are made about the level of under- humour as a welcome flavouring). The book should standing of the reader that may not prove to be true. prove useful to people seeking to couple research in In many settings, for example, one cannot assume that computer music and composition with an awareness of students will have a working familiarity with logar- psychoacoustics and the physics of sound. The content ithms – or be able to readily extend the idea of logar- is clearly defined by the historical trends of computer ithms into an understanding of decibel measures. Terms music research, and their unfolding at CCRMA in par- like ‘centroid’ or ‘inverse square law’ (or even the math- ticular. But that is probably good news for people ematical description of the Fourier series!) appear in the researching and teaching psychoacoustics in the com- text with little or no explanation. Materials that can puter music context. Portions of the book may prove less address some of these gaps can be found in the useful to people who do have an interest in music or Appendix. For example, the suggested exercises for Lab sound but not in computer music per se. The book seems 2 provide some elaboration on the difference between thoughtfully designed as a core text and resource for a linear and logarithmic scales and relates this to the cal- college course and will serve well as such coupled with culation of decibel measures. supplementary explanation. Though the book does not address aesthetic issues dir- ectly, the materials certainly hold aesthetic implications. Bret Battey Some of these seem likely to raise the eyebrows of com- posers inclined towards acousmatic theory or those seek- Patricia Kruth and Henry Stobart (eds.), Sound.New ing to make spatialisation a primary carrier of musical York: Cambridge University Press, 2000. 235 pp. ISBN meaning. In particular I refer to discussions of just 0-521-57209-6. RRP $34.95. noticeable differences in musical attributes and Shepard’s discussion of ‘dispensable versus indispens- God! Well, it starts with him and ends in ‘audiovisiogen- able attributes’ of musical sound. In a way, I wish that ics’. It is in fact 235 pages of reworked Cambridge the book had addressed the aesthetic issues head-on in Darwin College lectures from the 1997 series. ‘Some these contexts, though it is arguably out of scope. I find Aspects of Sound’ would have been a more descriptive it remarkable the degree to which discussions of music title. One might add ‘. . . without any sound’, since there theory are separated from discussions of psychoacous- are frequent references to sound recordings, but no CD. tics. Ultimately, music theory and psychoacoustic I imagine that the original lectures would have been research will be tightly linked. We may be a long way ‘illustrated’, or if you want to progress Michel Chion’s away from the time when that can occur in a truly sub- path, ‘audificated’. stantive fashion, but the implications of psychoacoustics There are nine essays: ‘Re-Sounding Silences’ (Philip research for music theory can be discussed now in such Peek), ‘The Physics of Sound’ (Charles Taylor), ‘Hear- a way that connections between the two areas are ing’ (Jonathan Ashmore), ‘Sounds Natural: The Song of encouraged. The book could be used to trigger such dis- Birds’ (Peter Slater), ‘The Sounds of Speech’ (Peter cussion in a classroom setting. Such a discussion could Ladefoged), ‘Ancestral Voices’ (Christopher Page), also touch on experimental design issues: In what fash- ‘Shaping Sound’ (Brian Ferneyhough), ‘Sound Worlds’ ion might aesthetic and cultural assumptions distort the (Steven Feld) and ‘Audio-Vision and Sound’ (Michel design of psychoacoustic experiments and interpreta- Chion). tion? There is actually a tenth essay, ‘Introduction’, by the Though the disc that comes with the book is labelled editors who do a very good job in pulling the fairly dis- as a CD-ROM, it is also an audio CD. Audio CD track parate elements together. Although their ‘linguastics’ numbers appear in Appendix C, listed in relationship to (you see, I’m already hooked on Chion’s proposal that the chapters. Note, however, that the text itself contains we need new words to describe new ideas and percep- no direct references to the disc; the relationships tions of air-vibrations and their interrelationships with between the sound examples and the text are implicit our senses) – linguistic gymnastics – are admirably rather than explicit. There were a few cases where it was inspirational, they still point out the fundamental prob- not clear to me how a given sound example related to the lem of describing and discussing aspects of sound with text. The CD-ROM portion of the disc contains , no sound. To signal that they knew it was the tenth ANSI-C, MIDI and PV-script sources for generating the essay, they end with six references for further reading. sound examples. This was a welcome surprise to me and Cleverly though, Kruth and Stobart introduce the theme can serve as a helpful resource to teachers, composers of silence as the first essay, neatly balancing this in their and researchers alike. The code is not commented for conclusion with an evocative description of one of John the most part, but the examples are probably simple Cage’s last performances, seventy-five minutes of enough to interpret and adapt despite this. ‘Empty Words’. Overall, Music, Cognition, and Computerized Sound ‘Re-Sounding Silences’ gets you into the swing by presents a fascinating range of information in a clear and asking more questions than it answers – for instance, accessible fashion (with occasional dabs of Perry Cook’s ‘Why is it that divine kings throughout Africa seldom Book reviews 113

speak publicly?’ The first three-quarters of this essay sensitivity in the region of 1,000–2,000 Hz.’ Ashmore tackles the phenomena of positive silences used in says, ‘we are most sensitive to sounds with a frequency ancient, non-European cultures. In his enthusiasm to of about 2000 Hz’. What neither says is that this is back up his case, Peek may be overstepping the mark by because the frequencies projected by the human mouth, stating that ‘ ‘‘normally’’ silent creatures are chosen for apart from the fundamentals, that enable us to distin- a range of significant communicative cultural functions guish between the fricatives – the sounds that clearly in the arts as well as religion’. What is not examined define the voice-projected word – are in this frequency here is the possibility that the many creatures that do region. From this, the question arises: Did speech make noise tend also to be unmanageable and very cap- develop to fill the ear, or did the ear develop to best able of damaging artist and cleric. The final quarter detect speech? So, this essay should really be called skims over the converse notion that ‘it is abundantly something like ‘Receptors in the Hearing Process’, but clear that Europeans worry about silence’. The clear fascinating nonetheless. non-abundance of examples unbalances this essay. ‘Sounds Natural: The Song of Birds’ covers exactly Nevertheless, I am drawn into the discussion and pro- what it says. Slater moves mellifluously through the sub- pose that, whether positive silence or positive sound, ject: ‘Why sound’, ‘How birds produce their sounds’, behind all this lies the perpetual scheming of the human ‘Sounds simple and complex: calls and songs’, ‘Why do animal, surviving through sound. birds sing?’, ‘Repertoire of songs’, ‘Song learning’ and Out of the forest, into the laboratory. ‘The Physics ‘Why learn?’. The essay, although brief, is peppered of Sound’ is a heavily abridged textbook. Although the with sonograms, graphs and tables. It encourages us into subject is better done by way of an ‘audificated’ lecture, the fascinating world of birdsong. Birds have two throats or full textbook, Taylor attracts us by describing the pro- within their syrinx, alternating between each or singing found impression that Dr Alexander Wood’s Cambridge two completely unrelated lines simultaneously, making sound lectures left on him. Those of us who know of them the ultimate double-trackers. Indeed, most of what Taylor’s animated and fascinating public lectures can they produce audibly is enriching, even if you are sur- ‘hear’ the examples as we read, but this easy dash rounded by trees and sleep with an open window in through the tubes of sound may not work so well for May! Again though, the book’s Introduction mentions a others. The subject of noise is rather side-stepped in Sound Event following the original live lecture. favour of an examination of tones and acoustics. Early in ‘The Sounds of Speech’, Ladefoged gives Through tones, the path of additive synthesis is fol- his game away by stating, ‘Now undoubtedly the most lowed, but the equal and opposite subtractive is not. important sounds for humans are those of language.’ Much of the world’s sound is made by nature’s modula- Predictably, what follows is rather long and dry. Will ton and filtering of noise, a model that has been con- the fact that the syllable ma has four different meanings tinued and developed as an essential ingredient in elec- in Standard Chinese when pitched differently and the tronic sound synthesis. My point here is that there is no syllable si up to six different meanings in Cantonese tone without noise, so the two extremes must be shown ever be remembered by anyone who either doesn’t know as equal and opposite. Taken at face value, this essay it already or is studying these specific intricacies? Will may fall between an over-long introduction to sound for the statement even be believed that, ‘In English, and in secondary school physics and a refreshing evocation for most European languages, the meaning of a word the initiated, minus the juice. remains the same irrespective of whether it is said on a ‘Hearing’ starts neatly with the inferred message that rising pitch or a falling pitch.’ Will you now try the there is much to do – the way is uphill: ‘Unlike the eye, following in the course of your daily diversions: say, about which Charles Darwin has much to say, the Origin ‘Yes!’ sharply in a low pitch – it means, ‘Yes!’; say of Species is silent about the ear.’ But this essay is actu- ‘Yes,’ starting at mid pitch, elongating the ‘e’ and drop- ally about the workings of the inner ear, and even that ping the pitch slowly – it means, ‘I don’t really believe becomes an introduction to the wondrous intricacies of you!’; say ‘Yes?’ quickly, starting at mid pitch and the cochlea. Here presented is much memorable mat- rapidly raising it – it means, ‘That’s preposterous – erial. Did you know that a hair cell doesn’t sport a hair you’re kidding – prove it!’. There are several others. But at all? Each cell offers around one hundred hair-like Ladefoged works in California, and we all know that sensors, stereocilia, whose physical movements are con- American is a different and difficult dialect of English. verted into electrical signals. It must be said that the title Not even Kruth and Stobart can fancy-foot their stride is a little misleading. This book is called ‘Sound’. into Page’s ‘Ancestral Voices’. He uses seventeen pages Sound, whether wanted or not, has to be interpreted, to discuss the fairly obvious fact that we can’t really consciously and unconsciously. Therefore, in ‘hearing’, know and consequently can’t provide an accurate repres- there has to be an element of ‘listening’, the individual’s entation of the sound of music before the advent of making sense of the sound. Maybe the fundamental idea mechanical recording. Somewhere hidden in the text is of ‘the whole picture’ is missing from this, and the pre- the idea that the social and philosophical views of the vious essay. Taylor says, ‘Most people have their highest time are part of any performed work and therefore we 114 Book reviews

would have to be there, to travel back in time, into the analyses are performed on the various isolated ingredi- smells, lifestyles and acoustics in order to hear, or better, ents, fragmenting and weakening that body. experience it in its original form and ‘frame’. But this Chion makes up several new words in his analysis. idea is not brought forward to balance his examination These will be either amusing or thought-provoking, and of the changes of voice tone and vibrato through the represent the exhilarating problem which, you will no centuries, for instance. However, the material that is pro- doubt have gathered, runs through the book – and a fair duced provides stimulation for our continued delving amount of our lifetime: how to represent or replace into the world of consonance and dissonance. sounds with words. Equally obvious by now are the wide Ferneyhough follows on to develop this in his ‘Shap- variation of methods suggested and the degrees of suc- ing Sound’ which, teasing his passion for alliteration, cess. Each chapter is followed by short helpful lists of could be ‘Sonic Simulation Style by Shaping Sentences’. Further Reading, five of which are extended with even The editors even admit that the text is ‘quite appropri- more helpful ‘and Listening’. ately, almost beyond words’. Style-warning aside, he The words are on a good if slightly thin glossy/chalky illustrates this study of twentieth-century music-making paper of 170 × 246 mm, with an ample 35 mm border all techniques in his sections, ‘Percussion, the urban sound’, round for you to compose your new words and generally ‘Sonorism and sound mass’, ‘Sonic innovation, critical annotate the whole volume. It’s certainly not an easy theory and social Utopia’, and ‘Parameter to spectrum: read, but offers stimulating rewards for perseverance, a material history of sonic legitimation’ with descrip- whether you’re a composer striving ever higher for tions of appropriate composers’ works supported by enharmonic clusters, a theoretician trading new words score examples. Early on, he proposes that a sudden for newer, or a sound buff attempting to understand and increase in percussion awareness, led by jazz and other unravel the string of sensorial vibrations that binds the ethnic vibrations, radically changed the sound world of universe. Western concert music in the twentieth century. I pro- pose that percussion was the battering ram that broke Ron Geesin the door down, but it was mechanical recording that excited the crowd to grab the ram. The moment it was David Cope, The Algorithmic Composer. Madison, WI: possible to record something unique, including the pre- A-R Editions Inc., 2000. 302 pp. with CD-ROM (Mac posterous, private and impossible, it was done – the format). ISBN0-89579-454-3. RRP $49.95. Okeh Laughing Record, various historical events, Beatrice Harrison (cello) with nightingales or church The Algorithmic Composer forms the last of a trilogy of bells, birdsong, tap-dancing. Add the like of these ingre- books following the development of David Cope’s work dients to various styles of music all into a ‘Gramophone in . The first was Computers Parlour’ at an Exposition in the early twentieth century and Musical Style, which appeared in 1991, followed in and you have an acoustically mixed model of much 1996 by Experiments in Musical Intelligence. All three music composition for the rest of the century. books appear in A-R Editions’ Computer Music and Feld exercises his anthropology in ‘Sound Worlds’. Digital Audio Series. He demonstrates his straddling of the seesaw of worlds Chapter One of the present volume is titled ‘Back- of sound and sounds of the world with one example of ground’ and first discusses some historical precedents each. The first part is a concise examination of the term, for algorithmic composition in the mainstream of and social implications of, ‘World Music’, from its birth musical history, going back to Philippe de Vitry’s com- as an academic convenience to its middle-age as a com- bination of color and talea in the isorhythmic motet of mercial success label. In direct contrast to this, he pre- the fourteenth century. In a relatively brief following sents the Kaluli tribe of Papua New Guinea, not quite section the author describes some contemporary algo- their world of sound but more their body of song, their rithmically based computer music programs, focusing on sound of word. While he is engagingly successful in Common Music, Patchwork and Symbolic Composer, pointing out in some detail the individual’s belonging to all of which, as it happens, employ LISP, as does Cope’s the song, and the reverse, he does not really study the own work. He then summarises his own earlier work ‘sound world’ of individuals in the tribe, although he as contained in the programs, Experiments in Musical repeats that phrase many times in the text. Intelligence (EMI) and Simple Analytic Recombinancy Concluding this cranial crunch of sonic s(t)imulation, Algorithm (SARA), and presents the case for a new pro- ‘Audio-Vision and Sound’ is an extra chapter. I imagine gram. This should be interactive, able ‘to keep a running this means that it wasn’t in the lecture series but Chion tabulation of the melodic, harmonic, motivic and struc- sold it to the editors later. This man is certainly a sales- tural content of a current work as well as maintaining a man: two-thirds of his Further Reading is by him. sense of a composer’s overall ongoing style’ (p. 35). Anyway, the essay grinds away in building support for Cope’s attempt to provide such a program resulted in my long-held theory that one receives a ‘sound film’ as the new program Alice (Algorithmically Integrated a homogenised body of audiovisual experience, but all Composing Environment), with which the rest of the too often the compositional methods and subsequent book is largely concerned. Book reviews 115

The next chapter, ‘Fundamentals’, describes some Alice can use to extend unity in a work. These are uni- smaller ‘tryout’ programs – those that Cope has fications and earmarks. Unifications are patterns found developed to explore ideas or certain aspects of pro- in a single work in a database that contribute to the unity gramming technique – which are presented on the of the work. Alice quantifies and types them, and CD-ROM and from Alice benefits to some degree. First employs them to extend music-in-progress in natural is ‘Fun’, a simple random drawing program, which pos- ways. Earmarks are patterns raised to the status of ges- sesses no claim to intelligence. The next program, ‘de´ja` ture, occurring in definite locations within a work, such vu’, performs a certain amount of analysis of what the as cadenza passages. user has drawn, and can consequently associate images As well as the pattern-matching and other analytical and classify them by name on the basis of the recognised tools employed by Alice, Cope has incorporated SPEAC features. The third is a natural language program called analysis. Derived from the theorist Heinrich Schenker’s ‘Backtalk’ that analyses typed responses from the user work, SPEAC stands for Statement, Preparation, Exten- and develops a primitive dialogue. sion, Antecedent and Consequent. Notes or phrases may The proclivity to the principles of analysis displayed be classified according to their function within the in these programs prepares us for the next chapter, titled musical continuity, and Alice can employ these classi- ‘Inference’. By this term Cope indicates the synergy of fications to assist larger-scale formal coherence. analysis and association, a prerequisite to any applica- Chapter Six, ‘The Alice Program’, describes in prac- tion of musical intelligence. There are interesting sec- tical terms how a composer might use the program. This tions on how Alice deals with voice leading (e.g. in tonal is appropriate, because a robust version of Alice is music), and with the analysis, processing and generation included on the CD-ROM, with source code for those of related pitch-class sets. Some may think that these users familiar with LISP who may wish to extend its techniques would be of little interest to many contem- functionality in ways suited to their own way of porary composers, but they do indicate a praiseworthy working. However, two points should be noted here. tendency on the part of the author to comprehensiveness. First, Alice as presented on this CD-ROM is a Macin- While the earliest versions of Alice used combinatorial tosh program, and there is a suggestion it may only be principles and augmented transition networks to develop suitable for a certain range of Macintosh computers, at that. Secondly, as Cope warns, the user should not ima- musical continuity, Cope felt the need for the application gine that composing with Alice is necessarily easier than of analysis on prior material (either in the form of an composing without its aid. The choice of the musical external database or within the current work-at-hand) to material for the database (typically, one or more earlier extend and deepen the musical connectivity. This is done works by the composer, or selected sections of such) is by allowing Alice to extrapolate rules according to an critical for matching to the analytical and compositional ingenious technique fully described in the book, choices the user extends to the program. A poorly employing the list-processing possibilities of his chosen matched database can only give poor results. language. This avoids the need for some explicit rule In use, Alice is likely to be highly interactive, with definition by the user. the user choosing databases, setting control thresholds Chapter Four, ‘Creativity’, expands the concepts of for the pattern matching processes, choosing the best Alice’s compositional principles by applying rules- output from those offered by Alice, and so on. Input is about-rules and going beyond the pitch paradigm to the via standard MIDI file, which may be supplied from the organisation of rhythm, dynamics and texture. Chapter user’s choice of notation program. Extended output can Five considers formal matters: structure and coherence also be converted from a standard MIDI file to conven- within an Alice composition. This is probably one of the tional notation, or can be heard directly via an appropri- most illuminating chapters for the reader who is interes- ate MIDI . While working with the program, ted in how Alice operates. The subject of musical signa- the user may choose from a number of displays of ana- tures is discussed: an important concept, which Cope lysis results: statistical graphs of pitch distributions, tex- introduced in the first book of the trilogy, and defined ture maps, etc. as ‘contiguous note patterns that recur in two or more Chapter Seven, ‘The Future’, discusses some short- works of a given composer, therefore indicating aspects comings of Alice, imagined or real, and some ways in of musical style’. Signatures may develop over time and which the program might be extended. Among the short- ‘can provide valuable insights into how a given style comings are those associated with MIDI, e.g. the diffi- matures’ (p. 148). Examples of signatures from a culty of varying the dynamics of a note during perform- number of classical sources are given. The process of ance, or of varying the articulation of instrumental signature recognition through pattern matching is indic- performance. Ways to personalise the program to con- ated, and extensions of this idea through hierarchical form to certain composers’ methods of working are sug- applications are shown, arriving at what Cope calls gested, and the implications of using very large data- ‘meta-patterns’, which Alice can use to match signatures bases, for example incorporating the works of several to their evolving musical contexts. composers, are explored. The main limitation at present Cope has also defined two further concepts, which for this is not just the amount of memory required, but 116 Book reviews

also the processing time for the multiple pattern- should be taking for algorithmic composition. The reli- matching processing and analysis that must take place. ance on a database of prior work which is then analysed Cope’s final statement of belief is optimistic: ‘I for tendencies for recombination, however sophisticated, believe that collaborative composition between humans is a bit like, as McLuhan put it, driving into the future and machine programs during the next millennium will with one’s eyes firmly on the rear-view mirror. Cope become more personal and more personally meaningful. appears to be aware of this: ‘I have been cautious in my Ultimately, the differences between human and machine estimation of the innovative worth of my ideas, prefer- that so many feel so acutely will disappear, and the two ring to believe that newness is often merely the embel- will seem as one.’ lishment of older, possibly less understood ideas. In all David Cope is to be commended in producing a book my work, there is a strong thread of reliance on extant of great interest and importance in the application of music rather than the development of new formulas.’ (p. computers to musical composition. He has been gener- 265) If a composing program relies on a database of ous in providing a major program, Alice, for algorithmic previously composed music, then however good the ana- composition on the CD-ROM, together with many lytical processes are, the resulting music can never be smaller programs of related interest, and performances better than the model(s) in the database. I feel, therefore, of the book’s musical examples. He appears to be invit- that Cope’s work should be viewed with great respect in ing collaboration from interested fellow-composers in the application of analytical principles to music, but developing Alice further and perhaps in personal direc- should be eschewed as a model for composition, which tions. Of special interest in Alice is the large number of must be allowed to give greater rein to new and possibly alternative forms of analysis that may be used – the pro- experimental modes of compositional strategy. An algo- gram can provide many ways of viewing what the com- rithmic system that permits such experimental thought poser is doing, to the point, undoubtedly, that may reveal is likely to give more exciting results, while no doubt unexpected if not unsuspected tendencies. presenting greater challenges to our current musical pre- As fascinating and worthwhile as the techniques Cope conceptions. has introduced undoubtedly are, I question whether this is the approach the informed composer–programmer Richard Orton