Computer Music Research Articles

Improved Methods for Statistical Modelling of Monophonic Music

N-Gram based models have been used for a variety of musical tasks including computer-assisted composition, machine improvisation, music information retrieval, stylistic analysis and cognitive modelling. We present an application-independent evaluation of some recent techniques for improving the performance of a subclass of n-gram models on a range of monophonic music data. We have applied these techniques incrementally to eight melodic datasets using cross entropy computed by 10-fold cross-validation on each dataset as our performance metric. The results demonstrate that significant and consistent improvements in performance are afforded by several of the evaluated techniques. We discuss the results in terms of previous research carried out in the field of data compression and with natural language and music corpora and conclude by presenting some important directions for future research.

Opening The Doors To Creativity: A Pre-Service Teacher Experiment

The purpose of the study was to document the compositional processes of pre-service teachers enrolled in a course entitled Creativity in the Music Classroom in an effort to contribute to the growing body of knowledge in this area as well as to encourage other tertiary-level teachers to introduce similar courses into the pre-service music teacher curriculum. The study charted the progress of nine students as they completed three individual composition tasks, one of which involved acoustic instruments and two of which were completed in the music computer lab. Data collection techniques consisted of observations, informal conversations with students and document analysis. Analysis consisted of studying the material culture and field notes, making marginal notes, sorting and coding. Student compositional processes were found to parallel those of participants in earlier research in that exploration, incubation/inspiration and revision were employed in varying degrees throughout. Prior music training, skills and knowledge were found to be both enabling and constraining influences whereas the open and trusting classroom atmosphere was noted by students as nurturing. Evidence of student compositional progress was demonstrated by increasing fluency of each successive student product.

Synthesizing Sound from Turbulent Field using Sound Textures for Interactive Fluid Simulation

Abstract Sound is an indispensable element for the simulation of a realistic virtual environment. Therefore, there has been much recent research focused on the simulation of realistic sound effects. This paper proposes a method for creating sound for turbulent phenomena such as fire. In a turbulent field, the complex motion of vortices leads to the generation of sound. This type of sound is called a vortex sound. The proposed method simulates a vortex sound by computing vorticity distributions using computational fluid dynamics. Sound textures for the vortex sound are first created in a pre‐process step. The sound is then created at interactive rates by using these sound textures. The usefulness of the proposed method is demonstrated by applying it to the simulation of the sound of fire and other turbulent phenomena. Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three‐Dimensional Graphics and Realism ‐ Animation; I.6.8 [Simulation and Modeling]: Types of Simulation ‐ Animation; I.3.7 [Computer Graphics]: Three‐Dimensional Graphics and Realism; I.6.3 [Simulation and Modeling]: Applications; H.5.5 [Information Interfaces and Presentation]: Sound and Music Computing ‐ Methodologies and techniques, Modeling.

Searching for lost data: outlines of aesthesic–poietic analysis

Fifty years down the line, the analysis of computer music is still a very complex issue, highly dependent on the identity of computer music itself: the variety of software, the lack of a common musical notation for scores, the absence or presence of computer data. This has led to the emergence of a multitude of analytical methods, including aesthesical analysis, which approaches music from the point of view of perception, and poietical analysis, which pays attention to the creative process.This study aims to combine these two methods of analysis in order to understand the relationship between technology and the actual piece of music. The article presents a methodological approach – focused on six pieces produced at IRCAM in Paris and at CSC in Padua, between 1975 and 1985 – via an in-depth consideration of Mauro Graziani's Winter leaves, a work conceived in 1980 at the CSC using Music360. The method used consists of comparing data collected using a diversity of practices: repeated listening, the tracing of graphical schematics, sonogram and spectrogram analysis, data listing analysis. An algorithm has also been created in order to calculate the degree to which the software is exploited and to enable a comparison between the different analyses. It is hoped that this procedure will combine traditional musicological methods with new approaches suited to the medium and grounded in a thorough knowledge of computer technology and musical environments.

“… computer music is cool!” Theoretical Implications of Ambivalences in Contemporary Trends in Music Reception

Technical innovations in the last years have decisively changed the ways in which we consume music. The use of the internet has led to an heretofore unknown expansion in the access to different kinds of music. Napster is the slogan which popularized the idea of searching the computer files of millions of computer users through a central server and of downloading a host of music titles in fairly good quality. Other “peer-to-peer”– systems (i.g. imesh) followed. This practice has led to an economic battle in which it is not always clear which side the combatants are on. Net pirates see themselves as a kind of computer vanguard and create a myth of digital heroism for themselves. In the center of this new mythology they place the pioneer, a cultural archetype with deep roots in the mythic history of the American continent and pop culture. This computer pioneer is a fighter for freedom in the name of a just cause. But the once wide gap between pioneers and the mass of average computer users has narrowed over the years. The easy accessibility of music has become part of a popular life-style as people tend to spend more time with the computer in chatrooms and other virtual digital worlds. Playful forms of consumerism are becoming more interesting in this context. It may be argued that Jeremy Rifkin’s “age of access” has already begun, the age in which the access to the thing, but not the thing itself is it. In the context of music consumption new processes of a fetishization of technology are taking place. Computer music is cool because of computer streaming techniques – a stance which obviously raises the question whether music is listened to at all. These trends will be discussed in their implications for a further development of music reception theory.

Generative Music and Laptop Performance

Live computer music is the perfect medium for generativemusic systems, for non-linear compositional constructions and forinteractive manipulation of sound processing. Unfortunately, muchof the complexity of these real-time systems is lost on a potentialaudience, excepting those few connoisseurs who sneak round the backto check the laptop screen. An artist using powerful software likeSuperCollider or PD cannot be readily distinguished from someonechecking their e-mail whilst DJ-ing with iTunes. Without a cultureof understanding of both the laptop performer and current generation graphicaland text-programming languages for audio, audiences tend to respondmost to often gimmicky controllers, or to the tools they have had moreexposure to – the (yawn) superstar DJs and their decks.This article attempts to convey the exciting things that are beingexplored with algorithmic composition and interactive synthesistechniques in live performance. The reasons for building generativemusic systems and the forms of control attainable over algorithmicprocesses are investigated. Direct manual control is set againstthe use of autonomous software agents. In line with this, four techniquesfor software control during live performance are introduced, namelypresets, previewing, autopilot, and the powerful method of livecoding. Finally, audio-visual collaboration is discussed.

Soundscapes

Today computer music is the dominant form of reproducedmusic and computers are widely available in the home and inscience laboratories. The advent of new technology prompts us torethink not only how we teach, but also what we teach. In thisarticle I present a possible new approach to the teaching ofsound based around these new technologies.

EDITORIAL

This issue of Organised Sound is about interactivity, a theme that the journal has often visited in the past. What makes this visit to this very important subject special is that it has been chosen as the first theme within our annual collaboration with the International Computer Music Association (ICMA). The ICMA President, Mary Simoni, has joined the Editors this year as ICMA representative and Mara Helmuth, currently the ICMA's editor of Array, has kindly taken on the role of Guest Editor for this issue. The journal Editors would like to welcome the ICMA and thank those ICMA members, and Mara in particular, who helped to make this issue possible. We look forward to further developing this collaborotion.

AI and music from composition to expressive performance

In this article, we first survey the three major types of computer music systems based on AI techniques: (1) compositional, (2) improvisational, and (3) performance systems. Representative examples...

EDITORIAL

As part of the evolution of our editorial structures for Volume 6 we were delighted to be able to establish a post on our Editorial Board for a representative of the International Computer Music Association (ICMA). We hoped to support the ICMA in a fruitful way, and I am now delighted once again to be able to announce that Organised Sound will be devoting its third issue annually to an ICMA theme and the work of the association's members (from Volume 7 Number 3). We hope that this will provide an additional dissemination vehicle for the organisation, allow its conference papers to be developed and expanded, provide an opportunity to publish work based upon the ICMA special interest groups and the association's affiliates. A representative of the ICMA will become a Guest Editor alongside the Organised Sound team of Editors and international referees for the third issue in each year.

Expanding contexts for computer music: one composer's experience

Using his own experience of forty-three professional engagements over a period of a year, most of which involved performances on a laptop computer, the author examines the nature of the ‘musical scenes’ into which involvement with computer music has led him. The author contends that the social nature of ‘computer music’ is changing not only because of changes in the technology, but also because of a number of social factors, some of which are examined in this article.

An echo from closed doors

On 31 December 1999 the La Trobe University Music Department closed its doors. From the outset, La Trobe Music saw itself as providing an alternative tertiary music education to the predominant paradigms of the time by fostering creativity through composition, technology, improvisation and other types of alternative performance practices. The philosophy of teaching electroacoustic music at La Trobe was to encourage students to find their own compositional voice rather than preach a particular style of electroacoustic music. The Department's research areas were in improvisation and technology, signal processing, gestural control devices, computer-assisted composition, analysis of electroacoustic music, realtime DSP, live electronics and installations. La Trobe's excellence in electroacoustic music was recognised by its inclusion in a survey of the world's top twenty-three computer music institutions by the Japanese journal Intercommunication 6. La Trobe staff and postgraduate students contributed papers and compositions to international and national computer music conferences and La Trobe was very much a part of the international community for over twenty-five years. The challenge now is for other Victorian institutions to meet the needs of today's students and to provide the deep research foundation in electroacoustic music that informs teaching and generates new music directions in the community.

The Aesthetics of Interactive Computer Music

This article describes the aesthetics of interactive computer music and contrasts these with aesthetic assumptions of other genres of computer music. Interactive computer music is a sub-genre of what might be called performance-oriented computer music-that is, any computer music that includes a strong performance component. This broader category requires at least one live performer joined with computer-generated or electronically produced or modified music. The genre thus incorporates both the traditional tape-plusinstrument medium (Mario Davidovsky's series of Synchronisms [e.g., Davidovsky 1988] are paradigmatic) and more recent interactive computer music-whether precomposed, improvised, randomly generated, or a mixture of these. I will narrow the focus of this article to just those works that are interactive: works wherein the performer in some way controls the electronics or the electronics affect the performer's sounds. The conceptual implications of this genre are rarely discussed. Even in works that purport to treat of the aesthetics of computer music in a general fashion, such as Keane (1986) and many essays in Heifetz (1989), the issues addressed fall short of those that are implied in addressing interactive computer music. Rather than merely creating a typology or presenting the more problematic aspects of its ontology, my aim will be to show what aesthetic qualities this music has that distinguish it from other genres of electronic and electroacoustic music as well as from other forms of music generally. Since aesthetic issues are intimately intertwined with value judgements, I also make some claims about the relative value of various approaches to computer-extended performance and their possibilities. After a brief discussion of some definitional and ontological issues (simply to set the boundaries of discussion), I turn to the main points of the article. These are considered under two broad, complementary headings: (1) the human performer's contribution to computer music, and (2) the computer's contribution to human performance. Within these broad sections, there is a background theme involving the nature and relationship of the human element to the machine element. In a great deal of music since the advent of electronic sound production, the electronic elements have been used to imply the non-human; this is one reason electronic music has been so often used in science fiction films. This is some-

Some Ontological Remarks about Music Composition Processes

However, the role of algorithms (finite computable functions, in Turing's sense) is not to be simply reified in a composition. Composers use computers not only as numbercrunching devices, but also as interactive partners to perform operations where the output depends on actual performance. Composers are concerned with the creation of musical situations emerging concretely of a critical interaction with their materials, including their algorithms. This task cannot be exhausted by a linear (a priori, non-interactive) problem-solving approach. Interaction is here matching an important feature of musical composition processes, giving room for the emergence of irreducible situations through non-linear interaction. Irreducibility is perhaps a key word in this context, as we are dealing with music's categories and ends. Music is not dependent on logical constructs unverified by physical experience. Composers, especially those using computers, have learned-sometimes painfully-that the formal rigor of a generative function does not guarantee by itself the musical coherence of a result. Music cannot be confused with (or reduced to) a formalized discipline: even if music actually uses knowledge and tools coming from formalized disciplines, formalization does not play a foundational role in regard to musical processes. I will refer in this article to a realist ontological principle relying on commitment to action which can shed light on the nature of musical compositional processes in regard to formal constructivism. Additionally, musical processes, at least from the composer's point of view, are not situations out there waiting to be discovered: they are rather to be composed (since they did not exist anywhere before being composed), and hence they cannot be considered properly as modeling activities, even if they use-and deeply absorb-models, knowledge, and tools coming from scientific domains (acoustic and psychoacoustic modeling, for example). In fact, music transforms this knowledge and these tools into its own ontological concern: to create specific musical situations (musical states of affairs). To this end, a palette of diverse compositional instances is needed, including strategies for controlling and qualifying results and choices, according to a given musical project. These compositional instances, to reiterate, are not envisaged here in the frame of the traditional approach to algorithmic (automatic) composition: they are instead seen in the light of the ongoing paradigm shift from algorithmics to interaction (Wegner 1997, Bello 1997), where the general-purpose computer is regarded as one component of complex systems (Winograd 1979), and where the composer, being another component of these complex systems, is imbedded in a network within which he or she can act, design, and experience concrete tools and (meaningful) musical situations. It is under this perspective, I believe, that the formal status of musical processes can be approachedin a certain way revisited-as I will try to do in this article, focusing on ontological questions. Computer music practice (computer-generated and computer-assisted composition) is of course the underlying frame of the discussion here offered, because these reflections have arisen from the

EDITORIAL

The final issue of Organised Sound Volume 5 represents the first step in what one hopes will become a fruitful long-term collaboration with the International Computer Music Association (ICMA). Selected papers from workshops and panels that formed part of the 2000 International Computer Music Conference (ICMC2000, Berlin, 27 August – 1 September) form the theme for this issue. Of the ten workshops and four panels, papers are being published representing two from each category. Obviously not all of these categories could be represented in this issue. Furthermore, it was clear that many of these workshops and panels would be difficult to translate into the form of an article.

Doctor Webern: A Visual Environment for Computer-Assisted Composition Based on Linear Thematism

For several centuries, imitation has supplied the locomotive force of counterpoint. Composers of different cultures, schools, and styles have constructed musical forms on the basis of relatively short themes passed among different voices with various delays and modifications. However, the problem of self-compatibility of the theme arises: how does one imitate the theme with the modifications of the same theme maintaining a certain vertical sonority at each instance, avoiding unwanted parallelisms and harmonies? The problem of this kind also arises when one tries to present several themes simultaneously or with a short delay. Few traditional quantified approaches to this problem exist that do not use a computer. One method is to compose the final part of a theme after integrating it into a polyphonic structure. Once we have found a certain combination, we can derive some child variants and try to connect them. This way of thinking yields more questions than answers, such as how to implement predefined themes and how to connect the derivatives if possible. On the other hand, the computer provides a means to quickly evaluate the large number of possible combinations. Now it is possible to directly analyze all possible combinations of all allowable modifications of predefined musical themes that satisfy a set of restrictions.

Computer-Assisted Composition at IRCAM: From PatchWork to OpenMusic

In recent years, IRCAM has been exploring and developing software for computer-assisted composition (CAC). These software packages allow composers and musicologists to formalize and experiment with the structures and dynamics of musical languages. The Formes program (Rodet and Cointe 1984), although primarily devoted to the control of sound synthesis, was really a compositional environment with a high-level object-oriented architecture. The Crime environment (Assayag, Castellengo, and Malherbe 1985; Amiot, Assayag, Malherbe, and Riotte 1986) was the first attempt at IRCAM to realize a general CAC environment where the user could define and control abstract musical formalisms. Francis Courtot developed CARLA as an attempt to use a visual programming interface to a Prolog-based logic-programming system (Balaban, Ebcioglu, and Laske 1992). The development of the PatchWork environment, by M. Laurson, J. Duthen, and C. Rueda (Laurson and Duthen 1989; Laurson 1996), was the next stage in the development of CAC programs at IRCAM. The combination of programming simplicity and a highly visual interface in a personal computing concept created an infatuation with PatchWork among European composers with highly diverse musical and aesthetic backgrounds, including Antoine Bonnet, Michel Fano, Brian Ferneyhough, Gerard Grisey, Paavo Heininen, Magnus Lindberg, Claudy Malherbe, Tristan Murail, Kaija Saariaho, and many others. OpenMusic, designed by G. Assayag and C. Agon (Assayag, Agon, Fineberg, and Hanappe 1997; Agon, Assayag, Delerue, and Rueda 1998), is the most recent IRCAM CAC environment. It is a visual interface to CLOS, the Common Lisp Object System (Steele 1990). Aside from being a superset of PatchWork, it opens new territories by allowing the composer to visually design sophisticated musical object classes. It introduces the maquette concept, which enables high-level control of musical material over time, and it revises the PatchWork visual language in a modern way.

Curtis Roads (with John Strawn, Curtis Abbott, John Gordon, and Philip Greenspun): The Computer Music Tutorial

Curtis Roads (with John Strawn, Curtis Abbott, John Gordon, and Philip Greenspun): The Computer Music Tutorial

GeNotator: an environment for exploring the application of evolutionary techniques in computer-assisted composition

A computer-assisted composition tool for investigating the application of evolutionary techniques in the composition of music is presented. The nature of such an application is examined in terms of defining the possible mechanisms that provide a means for automated creativity. These mechanisms take inspiration from processes found in Darwinian-based evolution theory, genetic algorithm theory and similar aesthetically based uses of a genetic search heuristic in the visual arts. A formal model of ‘musical evolution’ is proposed, with particular emphasis placed on the ways in which a genetic algorithm can be used to effectively manipulate a variety of compositional structures within a hierarchical and generative grammar-based model of musical composition. The result is a prototype Windows MIDI application called GeNotator that allows composers to experiment with a range of musical structures by interactively ‘evolving’ them through a familiar and comprehensive graphical user interface.

Data sonification and sound visualization

Sound can help us explore and analyze complex data sets in scientific computing. The authors describe a digital instrument for additive sound synthesis (Diass) and a program to visualize sounds in a virtual reality environment (M4Cave). Both are part of a comprehensive music composition environment that includes additional software for computer-assisted composition and automatic music notation.