Algorithmic Composition

In the field of computational creativity, the area of automatic
music generation deals with techniques that are able to automatically compose human-enjoyable music. Although investigations in the area started recently, numerous techniques based on artificial intelligence have been proposed. Some of them produce pleasant results, but none is able to effectively evolve the style of the musical pieces generated.

In this paper, we fill this gap by proposing an evolutionary memetic system that composes melodies, exploiting a society of virtual composers. An extensive validation, performed by using both quantitative and qualitative analyses, confirms that the system is able to evolve its compositional style over time.

Automatic music composition is a fascinating field within computational creativity. While different Artificial Intelligence techniques have been used for tackling this task, Planning an approach for solving complex combinatorial problems which can count on a large number of high-performance systems and an expressive language for describing problems has never been exploited.

In this paper, we propose two different techniques that rely on automated planning for generating musical structures. The structures are then filled from the bottom with “raw” musical materials, and turned into melodies. Music experts evaluated the  creative  output  of  the  system,  acknowledging  an  overall  human-enjoyable trait of the melodies produced, which showed a solid hierarchical structure and a strong musical directionality. The techniques proposed not only have high relevance for the musical domain, but also suggest unexplored ways of using planning for dealing with non-deterministic creative domains.

Music composition is a highly interdisciplinary process.To understand it deeply, a number of approaches have been used from different fields, such as musicology, music theory, music cognition and philosophy.    During  recent  decades,  numerous  techniques  based  on Artificial  Intelligence  (AI)  have  been  proposed.  In  particular,  many AI  systems  focus  on  automatic  melodic  composition.    Most  of  these systems  try  to  generate  melodies  enjoyable  by  a  human,  but  they completely ignore the way in which humans actually compose. Humans create  music  by  exploiting  a  mixed  top-down  bottom-up  approach,characterised by high-level cognition processes and rules.In  this  paper,  we  propose  a  memetic  model  for  music  composition,which  considers  both  psychological  and  social  levels.    The  former level  analyses  the  actual  cognitive  mechanisms  and  procedures  involved  while  composing  music:  namely,  museme  network,  compositional grammar and evaluation module. The social level puts the figure of the composer into perspective within her musical environment.  The introduced memetic model is encoded in a two-step algorithm.  Firstly,a  top-down  approach  is  used  for  defining  the  overall  structure  of  a melody.  Secondly,  the  given  structure  is  filled  with  musical  content,following a bottom-up strategy, that fosters emergent behaviour.  The proposed algorithm is the first system we are aware of which can evolve its own compositional style.  Stylistic change is achieved by modifying grammar rules and the museme network.  Finally, the paper provides an analysis of generated melodies.

We discuss here the function of the concept of algorithm in the musical production of non-computational works, generalizing the idea proposing it as an adequate tool for the conception of open works. The paper considers also the strategic use of the algorithm idea for musical works conceived as a poetic synthesis from determined authors and brings a brief analysis of the John Cage’s piece Music Walk (1958).

In this article a number of musical features are extracted from a large musical database and these were subsequently used to build four composer-classification models. The first two models, an if–then rule set and a decision tree, result in an understanding of stylistic differences between Bach, Haydn, and Beethoven. The other two models, a logistic regression model and a support vector machine classifier, are more accurate. The probability of a piece being composed by a certain composer given by the logistic regression model is integrated into the objective function of a previously developed variable neighborhood search algorithm that can generate counterpoint. The result is a system that can generate an endless stream of contrapuntal music with composer-specific characteristics that sounds pleasing to the ear. This system is implemented as an Android app called FuX.

The URL posted here links to general info, streamable audio files, downloadable .pdf file of the 24 page liner notes booklet for this album, which consists of some of the music I created at Bell Labs. during the 1970s on the GROOVE hybrid computer-controlled analog music system.

This dissertation presents the formalization of structural aspects within selected countermelodies by the Brazilian popular music composer Pixinguinha; with the intention of proposing a compositional model of idiomatic countermelody. Starting from the hypothesis that the musical elements within Brazilian musical genre Choro are arranged in a hierarchical way (ZISELS; AVELLAR; ALMADA, 2014), this dissertation explores the possibility of systematizing compositional practice within the genre. Which, in turn, serves as a theoretical frame for the exploration of different levels of structural importance. This research is comprised of both descriptive and statistical analyses. The descriptive approach is used in order to split key musical domains into smaller fragments. The statistical analysis addresses to the investigation of elements that fulfill either structural or superficial functions. In parallel, the probability data from a detailed examination of 19 Choros – a total of 57 independent parts – are used for a purpose-built software specifically constructed for algorithmic composition. We discuss the domains of rhythm and contour separately, before cross-referencing them for the purpose of producing a workable model. The formalism of the rhythmic domain is based on the assimilation of the concept of inter-onset interval (TEMPERLEY, 2001). The contour domain is systematized using the contour gestures approach, which is an appropriation of a methodological treatment of Jay Dowling (1978). The statistical data for each domain are carefully explored and a discussion of structural differences is proposed. The dissertation concludes with a detailed description of the compositional modeling process. The results are discussed and both the analysis and modeling point to promising paths for the continuation of the research.

Digital computers offer unprecedented flexibility and accuracy for the composition and performance of polytemporal music involving multiple time streams: polyrhythms, metric modulations, multiple tempi, and precisely calculated independent continuous tempo changes (accelerandi and decelerandi). This article addresses some important musical and technical issues encountered in music with multiple simultaneous tempi, including music with independently fluctuating tempi. The article includes a brief summary of some important precedents in pre-computerized music, a look at some implementations of polytemporality in computer music, and some suggested techniques for designing and manipulating multiple time streams in computer music composition.

Following a lifetime of creative work and investigation into algorithmic composition and microtonality, I became interested in the speculative mathematical music theory of Ervin Wilson. Encountering his work spurred me on to further investigations in sound and tuning, in a series of compositions using electronic, acoustic, and robotic acoustic instruments. Tuning ideas developed by Wilson and others were extended and

Digital sound synthesis can be described in terms of discrete operations applied to signals according to given criteria. The process of organising such operations can be subject to creative variation and generative algorithms. This article presents proposals for how a sound construction process can be thought of as a combination of synthesis and applied transformations. Operational spaces are examined and how process configuration and incompleteness can serve as creative models for synthesis. Properties of sound streams are also considered and how they can involve liveness and unpredictability. A software framework is finally introduced followed by a reflection on its use in creative practice.

This paper presents SonaGraph, a framework and an application for a simplified but efficient harmonic spectrum analyzer suitable for assisted and algorithmic composition. The model is inspired by the analog Sonagraph and relies on a constant-Q bandpass filter bank. First, the historical Sonagraph is introduced, then, starting from it, a simplified ("cartoonified") model is discussed. An implementation in SuperCollider is presented that includes various utilities (interactive GUIs, music notation generation, graphic export , data communication). A comparison of results in relation to other tools for assisted composition is presented. Finally, some musical examples are discussed, that make use of spectral data from SonaGraph to generate, retrieve and display music information.

There has been a significant amount of work implementing systems for algorithmic composition with the intention of targeting specific emotional responses in the listener, but a full review of this work is not currently available. This gap creates a shared obstacle to those entering the field. Our aim
is thus to give an overview of progress in the area of these affectively driven systems for algorithmic composition. Performative and transformative systems are included and differentiated where appropriate, highlighting the challenges these systems now face if they are to be adapted to, or have
already incorporated, some form of affective control. Possible real-time applications for such systems, utilizing affectively driven algorithmic composition and biophysical sensing to monitor and induce affective states in the listener are suggested.

In video games, music must often change quickly from one piece to another due to player interaction, such as when moving between different areas. This quick change in music can often sound jarring if the two pieces are very different from each other. Several transition techniques have been used in industry such as the abrupt cut transition, crossfading, horizontal resequencing and vertical reorchestration among others. However, while several claims are made about their effectiveness (or lack thereof), none of these have been experimentally tested.

To investigate how effective each transition technique is, this dissertation empirically evaluates each technique in a study informed by music psychology. This is done based on several features identified as being important for successful transitions. The obtained results led to a novel approach to musical transitions in video games by investigating the use of a multiple viewpoint system, with viewpoints being modelled using Markov models. This algorithm allowed the seamless generation of music that could serve as a transition between two composed pieces of music. While transitions in games normally occur over a zone boundary, the algorithm presented in this dissertation takes place over a transition region, giving the generated music enough time to transition.

This novel approach was evaluated in a bespoke video game environment, where participants navigated through several pairs of different game environments and rated the resulting musical transitions. The results indicate that the generated transitions perform as well as crossfading, a technique commonly used in the industry. Since crossfading is not always appropriate, being able to use generated transitions gives composers another tool in their toolbox. Furthermore, the principled approach taken opens up avenues for further research.

In this study, psychological perspectives are used to discuss the emotional impact of music. The main aim of this research is to define a set of compositional elements that can influence, in a predictable manner, the emotional state of the listener. Those elements are then applied to a compositional method used by a digital instrument which are programmed for this experiment to generate music patterns based on the emotional impact the composer wants to create. To succeed in this, the findings have to be subjectively tested using self-report analysis and through data collection translated into more objective data. The resultant instrument represents a strong compositional tool offering more clarity and universality, with a new language for compositional purposes based on the emotional character of musical elements, which can be similarly interpreted from different listeners perspectives.
To achieve this, elements biologically connected to our emotional system need to be defined, selected, and tested individually with appositely designed surveys, whereas  the results are essential to define the correlation between the different elements of the digital instrument programmed with Pure Data. Once the determinate of the correlation between the elements has been identified, the instrument should be able to contextualise the elements previously tested individually and provide a more natural and powerful controlled emotional impact on listeners.

This report accompanies the author’s graduation project for fulfillment of the EMMA at the Hogeschool voor de Kunsten in Utrecht. In chapter 1 the research question and objectives
of the project are stated, which can be summarized as follows: To explore the artistic possibilities of mapping a mathematical grounded model onto musical parameters to design and control electronic sounds and to use the same model to generate larger-scale musical structure and form. These experiments have culminated in an algorithmic sound composition in which the designed mappings are used as effectively as possible. The motivation for carying out this project is primarily out of a general interest with regards to making music and designing sounds from a creative perspective, developing software from a technological perspective, but also to seriously study and apply theoretical physics and mathematics.

The presentation of the results of the project is preceded by a critical review of relevant
work and repertoire by others in chapter 2. It discusses literature concerning the mapping of
equations to musical parameters, but also some more generalized software implementations,
musical works and compositional strategies.

Chapter 3 is devoted to the derivation of the Schrödinger equation and its solution for the hydrogen atom. The mathematics involved might be rather challenging for the
unexperienced reader, but the discussion will be kept as simple as possible and there will be references to more specialized literature whenever necessary. The chapter ends with some graphical examples of the designed software implementations of the solutions of the Schrödinger equation for a hydrogen atom. The SuperCollider classes that govern this implementation are part of the MathLib Quark which is publicly available for download.

Chapter 4 is a detailed technical description of the project and the algorithmic sound composition in which the technical implementation of the designed algorithmic methods and
techniques is described as well as the sound synthesis model used for the generation of all sounds.

Chapter 5 is an evaluation of the project from a number of different perspectives and tries to answer the research questions posed in chapter 1. In addition, a number of alternative tests are conducted to justify the choice of working with the Schrödinger equation from a musical point of view.

In the last chapter, the strength and weaknesses of the design process, the programmed software and sound composition are summarized and a number of suggestions are made for future experiments and subjects to focus on.

All available sound material that is related to the project is included on the cd accompanying this report or alternatively, can be listened to at http://www.soundcloud.com/michaeldzjap.

The better quality pdf is downloadible from here: "http://www.leoalmanac.org/wp-content/uploads/2013/07/LEAVol19No3-Mailman.pdf
Through recent artistic practices and technology of interactive systems for music, composition and improvisation have more and more blended and interconnected with each other – a sui generis situation now called comprovisation. The concept of comprovisation applies equally well to the spontaneous generation and manipulation of computer graphics, especially as such graphics are systematically coordinated audio-visually, while being subject to spontaneous manipulation by a performer.
This is explained in terms of the Fluxations and FluxNoisations Human Body Interfaces, interactive dance systems that generate music and graphics spontaneously in response to hand and body movement. They enable spontaneous expressive shaping of coherent complexity and variety. Thus a multi-layered multimodal experience arises. The aesthetic experience of this multimedia spectacle relates to experiences of various prior music and visual art of the 19th, 20th, and 21st centuries, as well as to hypothetical physical realities. Thus a kind of cybernetic phenomenology of art is pursued and enacted through an embodied cybersynthesis of art with simulated alternate reality. Call it a pragmatic speculative realism, an adventurous technoetic ‘what if.’ As compared to more traditional forms of improvisation, the opportunities for risk-taking and aesthetic exploration rise to a new level of uncertainty, as the reactions of the improviser simultaneously draw from and target both visual and aural modalities, such that the intentions toward each fuse together."

In this thesis, I seek to explore alternative ways of thinking about sound material and different strategies to treat this material in time, namely by the usage of generative algorithms and a network-inspired data flow. For this purpose, I have designed and implemented a framework that is meant to facilitate this exploration in the context of computer music composition; it is therefore a dissertation concerned with aspects of relationships, inter- dependencies and interactions of sound objects. A detailed account of these processes will be covered along with musical concerns that motivated the creation of the framework. The chosen environment for the implementation of the system is SuperCollider. The thesis will cover as well examples of own compositions made with the framework and a concise analysis of potentials and consequences of these strategies.

Despite the still-prevalent but essentially nineteenth century perception of
the Western creative artist, an algorithmic approach to music composition has been in
evidence in Western classical music for at least one thousand years. The
history of algorithmic composition---from both before and after the invention
of the digital computer---will be presented along with specific techniques and
musical examples from the distant and recent past.

This article deals with the philosophical idea of worldmaking pursued through techné, meaning the fusion of the technical means of artistic creation, theorizing, and analysis, but specifically occurring in a feedback loop involving introspection and computation (cybernetic phenomenology). The discussion ranges over a wide variety of topics, including (1) the history of music theory from Ancient Greece to the present (including a rebuttal to Daniel Chua’s (2001) account of music history); (2) emergent properties in music arising from self-organization (explored through the Ancient Chinese abstract strategy board game go); (3) the ontology of musical qualities (properties) and categories (including their relation to visual, tactile, and olfactory qualities and categories). 
Various repertoires, artists, and philosophies are referenced. The essay analyzes aspects of Ligeti’s Violin Concerto, Carter’s String Quartet No. 5, and Lachenmann’s Kinderspiel.  Connections to the author’s own previous analytical and theoretical work are also discussed in relation to his interactive algorithmic audio-visual works (such as Fluxations and FluxNOISations). The techné of these is discussed in terms of logistics as well as aesthetic influences, including Wagner, Liszt, Stravinsky, Schoenberg, Crawford, Babbitt, Carter, Xenakis, Parker, Reich, Ligeti, Truax, Oliveros, Kandinsky, Miro, Pollock, Pollock, Hofmann, Rothko, Louis, Frankenthaler, Moholy-Nagy, Newman, Richter, and Brakhage.  The essay touches on philosophical ideas of Bergson, Whitehead, Deleuze, Harman, and Bogost, and more fully engages the philosophies of Nelson Goodman and Hannah Arendt in connection with artistic creation as relating to the theorizing and analysis of artistic works.     

Contact the author at [email protected]
Download the article through JSTOR: http://www.jstor.org/stable/10.7757/persnewmusi.54.1.0005
or http://tinyurl.com/zdvkllr

Post-Anthropocentric Creativity; Call for Submissions, special issue of Digital Creativity, 27:1, January 2016; Guest editors: Stanislav Roudavski and Jon McCormack. This special issue aims to audit existing conceptions of creativity in the light of non-anthropocentric interpretations of agency, autonomy, subjectivity, social practices and technologies. Specifically, it seeks to explore how 1) the agents, recipients and processes of creativity and 2) the purpose, value, ethics and politics of creativity relate to phenomena of computation. The editors encourage innovative narrative or visual strategies that can express relevant scenarios better that more typical forms of academic writing. Dialogues, conversations, plays, scripts, instruction sets, games or visual essays (for example) might be suitable alongside logical arguments or formulae.

Esta pesquisa sistematiza um catálogo de experimentos constituído de estudos musicais e seus algoritmos geradores, organizando procedimentos para composição assistida por
computador orientados por regras derivadas de análises musicais de contexto pós-tonal.
Os procedimentos são inspirados em apontamentos de estudos sobre pós-tonalidade no compositor Béla Bartók, encontrados nas obras de Lendvai (1971), Antokoletz (1984),
Cohn (1991) e Suchoff (2004). Problematizam-se aqui os conceitos de ciclos intervalares, eixos de simetria, polimodalismo e peculiaridades de coleções referenciais de classes de altura - conforme sugestões de Forte (1973), Straus (2004) e Susanni e Antokoletz (2012).
São detalhadas questões computacionais para esta implementação, utilizando como base as ferramentas OpenMusic e biblioteca Python Music21.

This research presents the design, usage, and evaluation of a highly generic music con- straint system called Strasheela. Strasheela simplifies the definition of musical constraint satisfaction problems (CSP) by predefining building blocks required for such problems. At the same time, Strasheela preserves a high degree of generality and is reasonably efficient.

Strasheela is highly generic, because it is highly programmable. In particular, three fundamental components are more programmable in Strasheela compared with existing music constraint systems: the music representation, the rule application mechanism, and the search process.

Strasheela features an expressive symbolic music representation. This representation sup- ports explicitly storing score information by sets of score objects, their attributes, and their hierarchic nesting. Any information available in the score is accessible from any object in the score and can be used to obtain derived information. The representation is complemented by the notion of variables: score information can be unknown and such information can be constrained.

This research proposes a rule formalism which combines convenience and full user con- trol to express which score variable sets are constrained by a given rule. A rule is a first-class function. A rule application mechanism is a higher-order function. A rule ap- plication mechanism traverses the score in order to apply a given rule to variable sets. This text presents rule application mechanisms suitable for a large set of musical CSPs and reproduces important mechanisms of existing systems.

Strasheela is founded on a constraint programming model which makes the search process programmable at a high-level. The Strasheela user can optimise the search for a partic- ular constraint satisfaction problem by programming a distribution strategy (a dynamic variable and value ordering) independent of the problem definition. Special distribution strategies for efficiently solving various musical CSPs – including complex polyphonic problems – are presented.

Morris's Arc (1988) for String Quartet flows; it flows with substance, and with purpose. By flowing, I don’t just mean in the trivial sense that all music flows because it is unfolding in time and time flows. Rather I mean that there is continuity to its various surges of eventfulness; these surges are not disjunct or sudden. And by substance I mean both that its sound is as a sensuous fluid material and that the unfolding of its constituent events presents a coherent organization, thus binding together into a statement that seems meaningful in retrospect. By purpose I mean not only that there is a local logic to the consequence of one note following another, but also that the flow of events enables the material to organize into processes that forge a trajectory toward a goal.
    The analysis first focuses on local details considered in terms of pitch and pitch-class formations as arising from twelve-tone rows; then it delves into aspects of form, process, and texture. These are considered in terms of emergent properties in flux. The modeling of these properties and their flux employs some mathematical formalisms, but the reader can rely on the fact that every mathematical definition and formula is described carefully in prose as well.
    In Arc, the twelve-tone pitch class details and the surging emergent qualities projecting form are not completely separate from each other. Rather, all these features interact. Thus not only does the article weave together connections between such facets as form, process, and texture, but it also connects these to the twelve-tone rows and pitch-class configurations that are more straightforwardly part of the compositional plan (and more usual in analyses) of Morris’s music.

[Download the pdf below, or contact the author [email protected], for a digital offprint. It can also accessed through JSTOR: www.jstor.org/stable/10.7757/persnewmusi.52.2.0249 ]

Is the margin for atypical musics in worship more accommodating than we think?    Considering the vastness of popular art forms, what other musics or music practices beyond the pop-influenced Praise Team might also resonate within worship contexts?  Composers John Cage and Tom Johnson continue to have cross-cultural appeal amongst musicians and listeners; their music is playable and perform-able by many different ensembles.  Do these musics or does this school of musical activity have purchase in liturgical contexts?  Does such music jibe with the current "Traditional" and "Contemporary" dichotomy, or does it demand its own category?  This paper explores the inclusion of atypical musics in liturgical practice, with "atypical" defined only by works' heretofore lack of presence within the church.  I draw on field research conducted at the Congregational churches where I served as Minister of Music from 2008-2014.  Here, music involving Cage-ian tactics, secular popular musics (of non-liturgical origin), and traditional Ghanaian songs and rhythms constitute a significant portion of worship music.  I argue that deploying aleatoric (indeterminate) devices in the music-making, in concert with recognizing congregational proclivities towards particular supercultural songs, fosters a church's autonomy in crafting its own musical language or identity.  This animates an aesthetic ecology, where site-specificity plays a curatorial role.  Instead of musics determined by culture-wide dichotomies that tend towards top-down cultural dissemination (from publishing houses or centralized denominational headquarters), I propose that churches themselves take on the project of cultural production, tuning in to the ecological factors present in the extant faith community.  In forming this discussion, I refer to my training as a composer, ethnomusicologist, pipe organist, and upbringing as a Reformed Jew.