Apprentissage de structures multi-dimensionnelles pour l'improvisation musicale

National audienceL'improvisation automatique est un domaine récent issu des études sur la créativité artificielle. Les systèmes actuels d'improvisation automatique sont capables de prendre en considération des informations unidimensionnelles, typiquement la mélodie, fournies en direct par un musicien ou lues dans un corpus afin de générer de nouvelles improvisations par une recombinaison du matériau musical. Cependant, ils ne sont pas capables de prendre en considération des informations multi-dimensionnelles. Or la musique comporte de nombreuses dimensions : mélodie, harmonie, rythme... Dans ce rapport, nous évaluons l'intérêt de prendre en compte plusieurs dimensions musicales dans le cadre de l'improvisation en appliquant des méthodes d'interpolation de sous-modèles issues du domaine de l'apprentissage automatique et des principes de modélisation de langage. Nous effectuons l'apprentissage et les tests sur un corpus d'improvisation de jazz. Nous évaluons les résultats en comparant leurs entropies croisées. Nous montrons que dans certains cas, l'interpolation de sous-modèles permet d'obtenir un meilleur pouvoir de prédiction que lorsque l'on ne considère qu'une seule dimension musicale. Mot-clefs : improvisation automatique, apprentissage automatique, modélisation du langage

AN APPROACH TO MACHINE DEVELOPMENT OF MUSICAL ONTOGENY

This Thesis pursues three main objectives: (i) to use computational modelling to explore how music is perceived, cognitively processed and created by human beings; (ii) to explore interactive musical systems as a method to model and achieve the transmission of musical influence in artificial worlds and between humans and machines; and (iii) to experiment with artificial and alternative developmental musical routes in order to observe the evolution of musical styles. In order to achieve these objectives, this Thesis introduces a new paradigm for the design of computer interactive musical systems called the Ontomemetical Model of Music Evolution - OMME, which includes the fields of musical ontogenesis and memetlcs. OMME-based systems are designed to artificially explore the evolution of music centred on human perceptive and cognitive faculties. The potential of the OMME is illustrated with two interactive musical systems, the Rhythmic Meme Generator (RGeme) and the Interactive Musical Environments (iMe). which have been tested in a series of laboratory experiments and live performances. The introduction to the OMME is preceded by an extensive and critical overview of the state of the art computer models that explore musical creativity and interactivity, in addition to a systematic exposition of the major issues involved in the design and implementation of these systems. This Thesis also proposes innovative solutions for (i) the representation of musical streams based on perceptive features, (ii) music segmentation, (iii) a memory-based music model, (iv) the measure of distance between musical styles, and (v) an impi*ovisation-based creative model

Singing in Action : An inquiry into the creative working processes and practices of classical and contemporary vocal improvisation

This dissertation explores performative perspectives on classical and contemporary vocal improvisation (CCVI) as a critical, creative tool for development of and research in vocal performance. It consists of one introductory part and five articles, with additional documentation on a homepage. The artistic projects have been performed in close collaboration with fellow classically trained singers and musicians. The practice of CCVI is contextualised in relation to vocal history, opera, improvisation practice(s) and research in vocal performance. The artistic methods of opera improvisation, lyrical improvisation and CCVI without words are described in text and video. The studies performed also investigate how theoretical concepts such as performativity, action and interperformativity can be used for articulating aspects of communication, creativity and knowledge in CCVI. Central to the thesis is a suggested model for analysing performativity in three dimensions: the structural, the symbolic and the individual. Performative aspects of the singer’s subject positions as a vocal and instrumental persona in a classical vocal concert approach and an opera performance approach are articulated and problematised in the artistic practice. New artistic performance concepts and projects are presented. CCVI is used as a creative artistic tool for singers in critical dialogue with classical vocal performance tradition: deconstructing methods of portraying gender and power in operatic performance; opera improvisation with symphonic orchestra; composed and improvised opera with choirs; abstract improvisation in dialogue with visual art; improvisation with poetry and electronics and deconstructing Lied performance in dialogue with light design. An interview study focusing on the experiences and perspectives of the improvisers indicate that presence, relations to one another in the ensemble, relations to the emerging material, and the creation of common agreements and structures are central in CCVI. Three analytical models focusing on interaction in CCVI are presented: action analysis in improvisation, the Interplay Analysis Model and the use of the concept musico-performative tropes. It is suggested that improvisers in CCVI create music, text and dramatic content as vocal and musical actions by the intuitive use of musical and performative tropes in an interperformative play with the performance context as well as the classical singing tradition

A Novel Interface for the Graphical Analysis of Music Practice Behaviors

Practice is an essential part of music training, but critical content-based analyses of practice behaviors still lack tools for conveying informative representation of practice sessions. To bridge this gap, we present a novel visualization system, the Music Practice Browser, for representing, identifying, and analysing music practice behaviors. The Music Practice Browser provides a graphical interface for reviewing recorded practice sessions, which allows musicians, teachers, and researchers to examine aspects and features of music practice behaviors. The system takes beat and practice segment information together with a musical score in XML format as input, and produces a number of different visualizations: Practice Session Work Maps give an overview of contiguous practice segments; Practice Segment Arcs make evident transitions and repeated segments; Practice Session Precision Maps facilitate the identifying of errors; Tempo-Loudness Evolution Graphs track expressive variations over the course of a practice session. We then test the new system on practice sessions of pianists of varying levels of expertise ranging from novice to expert. The practice patterns found include Drill-Correct, Drill-Smooth, Memorization Strategy, Review and Explore, and Expressive Evolution. The analysis reveals practice patterns and behavior differences between beginners and experts, such as a higher proportion of Drill-Smooth patterns in expert practice

Religious musical performance as an articulation of transformation : a study of how the Tsonga Presbyterians of the Presbyterian Church of Mozambique negotiate their indigenous Tsonga and Swiss reformed church heritages

The Presbyterian Church of Mozambique (IPM) has its origins in the Swiss Mission and the European Reformed Church. An ethnomusicological study was conducted on the music of the IPM in order to uncover its musical influences. The musical influences were found to pertain to an indigenous Tsonga musical character, as well as to a Reformed Church musical tradition. By situating the discussion in this thesis within the perspective that music may reflect that which is not explicitly spoken about in words, the music of the IPM was shown to reflect the dual-heritage of the members of the IPM. Thus, this thesis attempts to answer the questions: how is the music of the IPM a reflection of the Tsonga Presbyterians’ dual-heritage?; and how do the Tsonga Presbyterians negotiate their dual-heritage? It was found that the Tsonga Presbyterians negotiate their dual-heritage by blending a Reformed Church performance style with a Tsonga one. For example, the music in the form of hymns and church songs, performed by church choirs, is shown to be didactic in nature where the lyrics are the most important aspect of the music. The didactic nature of the music is a principle of the Reformation carried forth in the music of the IPM. Although music serves to transmit the Christian message and is used as a means of praising the Christian God in the IPM, it also exists on the level in which the indigenous Tsonga heritage may be incorporated into the Christian lives of the members of the IPM without having an impact on the Reformed Church belief system. This is where the members have the freedom to blend their musical heritages. Music, in this instance, is shown to be a powerful tool by which the importance of an indigenous, and an appropriated, heritage may be garnered and observed.Looking to the historical aspects of the IPM, the music and language literacy education, provided by Swiss missionaries on the mission stations, was shown to have had an influence on Tsonga hymn composition. Along with the mobile phone, the observed decrease in music literacy at Antioka was situated within a discussion that looked at the influence of these aspects on the transmission, conservation and continuation of music in the IPM. Throughout the thesis, social transformation is referred to and the manner in which the music of the IPM is conserved or continued is an indication of how musical transformation may reflect social transformation

Explaining Listener Differences in the Perception of Musical Structure

PhDState-of-the-art models for the perception of grouping structure in music do not attempt to account for disagreements among listeners. But understanding these disagreements, sometimes regarded as noise in psychological studies, may be essential to fully understanding how listeners perceive grouping structure. Over the course of four studies in different disciplines, this thesis develops and presents evidence to support the hypothesis that attention is a key factor in accounting for listeners' perceptions of boundaries and groupings, and hence a key to explaining their disagreements. First, we conduct a case study of the disagreements between two listeners. By studying the justi cations each listener gave for their analyses, we argue that the disagreements arose directly from differences in attention, and indirectly from differences in information, expectation, and ontological commitments made in the opening moments. Second, in a large-scale corpus study, we study the extent to which acoustic novelty can account for the boundary perceptions of listeners. The results indicate that novelty is correlated with boundary salience, but that novelty is a necessary but not su cient condition for being perceived as a boundary. Third, we develop an algorithm that optimally reconstructs a listener's analysis in terms of the patterns of similarity within a piece of music. We demonstrate how the output can identify good justifications for an analysis and account for disagreements between two analyses. Finally, having introduced and developed the hypothesis that disagreements between listeners may be attributable to differences in attention, we test the hypothesis in a sequence of experiments. We find that by manipulating the attention of participants, we are able to influence the groupings and boundaries they find most salient. From the sum of this research, we conclude that a listener's attention is a crucial factor affecting how listeners perceive the grouping structure of music.Social Sciences and Humanities Research Council; a PhD studentship from Queen Mary University of London; a Provost's Ph.D. Fellowship from the University of Southern California. This material is also based in part on work supported by the National Science Foundation under Grant No. 0347988

Open, mobile and indeterminate forms

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Since the early fifties “open form” has become a generic description for many different compositional concepts having in common musical outcomes which to a certain degree are indeterminate. The introduction looks into different meanings given to “form” in music and gives a historical survey of the origins of compositional indeterminacy. Next, the concept of “open form” is elaborated into a territory which is usually not associated with it: jazz. The introduction is followed by five case studies. Folio (1952-54) by Earle Brown is considered to contain the first intentionally “open form” works. It is driven by improvisational ideas, either at the compositional stage or at the interpretative stage. Brown's affinity with jazz also offers connections to other topics of the thesis. Miles Davis' Ife (1972) may at first seem like an odd inclusion in this study, but it is not. Its only oddity could be that of all the works discussed it has no score. But it is a composition; it is recognizable throughout its various incarnations and repeatable, and its outcome is indeterminate. Adam Rudolph did not conceive Ostinatos of Circularity as an “open form” work, but it is an indeterminate composition: it does have a score the musical result of which depends on the decisions made by the composer/conductor during the performance as well as the choices made by the performers. In Peter Zummo's Experimenting with Household Chemicals the performers play the same, often ambiguous, score, moving in the same direction at their own speed and discretion. The lack of synchronicity and the ambiguous notation result in a very elastic organic form. Anne La Berge refers to her recent works as “guided improvisations”. The scores mainly consist of suggestive text materials, software preset descriptions and rudimentary verbal indications, leaving major decisions to the performers. The last chapter is about my own work. It presents seven works (the scores of which can be found in the accompanying portfolio), composed between 2007 and 2011. Each of these works uses the score as a “field” through which the performers roam

Music and time: tempomorphism: nested temporalities in perceived experience of music.

This thesis represents the results of a theoretical and practical investigation of acoustic and electro-acoustic elements of Western music at the start of the twentyfirst century, with specific attention to soundscapes. A commentary on the development of soundscapes is drawn from a multidisciplinary overview of concepts of time, followed by an examination of concepts of time in music. As a response to Jonathan Kramer's concept of `vertical' music (a characteristic aesthetic of which is an absence of conventional harmonic teleology), particular attention is paid to those theories of multiple nested temporalities which have been referred to by Kramer in support of non-teleological musical structures. The survey suggests that new musical concepts, such as vertical music, have emerged from sensibilities resulting from the musical and associated styles of minimalism, and represent an ontological development of aesthetics characteristic of the twentieth century. An original contention of the debate is that innovations in the practice of music as the result of technological developments have led to the possibility of defining a methodology of process in addition to auditive strategies, resulting in a duality defined as 'tempomorphic'. Further observations are supplied, using findings derived from original creative practical research, to define tempomorphic performance, which complete the contribution to knowledge offered by the investigation. Tempomorphism, therefore, is defined as a duality of process and audition: as auditive tool, tempomorphic analysis provides a listening strategy suited to harmonically static music; as a procedural tool, it affords a methodology based primarily on duration

Physical theatre as an approach to contemporary stagings of classical Greek tragedy

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This PhD focuses on physical theatre techniques and practices in order to provide acting keys for directing ancient drama. More specifically, the work for stage put effort in the acting method, with which the chorus and the main characters can be approached. For that reason, the basic method adopted was that of J. Lecoq, and especially the ‘transference’ practice. Moreover, specific elements were selected from the methods of: the Laboratory theatre of J. Grotowski, the Odin Teatret of E. Barba, and from K. Stanislavski’s practice of physical actions. Elements were also incorporated from modern dance techniques (M.Graham, P. Bausch and R. Laban), as well as from Dramatic play. The first part of the PhD summarizes theoretical aspects on the tragedy’s structure through the written material that has survived from antiquity. The ancient drama history, the history of acting and directing tragedy, as well as other interpreting matters are analyzed. Moreover emphasis has been placed on Euripides’ whole work, on the historical and cultural frame of writing the Bacchae, as well as on ideological aspects and comments on the roles. Finally, material for the most important performances, which took place in Greece, is given. In the second part of the thesis an experiment has been performed between the classic speech of tragedy and contemporary methods of movement and speech. The aim was to investigate how these function together, by applying them on the text of Bacchae. Although the stress on the body pre-existed in acting methods of several directors, the specific method of Physical theatre was applied around 1955 from J. Lecoq. Since in Physical theatre the physical expression is symbolic, non-realistic, with a heightened sense of theatricality, this method can provide to tragedy the suitable acting tools for the big statures of the roles-symbols and for the meaningful movement of the chorus. Physical theatre does not emphasize on the character and his behavioural gestures but on the situations themselves and how the actor undertakes them. Therefore it can complement word-based theatre, which focuses on the acts emerged from the myth and on the creation of mimetic archetypes. In that way, the demonstrated actions and the messages conveyed through them, become essential and represent the collective unconscious. Consequently, if tragedy expresses symbols, emphasizes on the myths’ acts and detaches from realism then it is proved that the method of Physical theatre can be an appropriate method