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

Ontology of music performance variation

Performance variation in rhythm determines the extent that humans perceive and feel the effect of rhythmic pulsation and music in general. In many cases, these rhythmic variations can be linked to percussive performance. Such percussive performance variations are often absent in current percussive rhythmic models. The purpose of this thesis is to present an interactive computer model, called the PD-103, that simulates the micro-variations in human percussive performance. This thesis makes three main contributions to existing knowledge: firstly, by formalising a new method for modelling percussive performance; secondly, by developing a new compositional software tool called the PD-103 that models human percussive performance, and finally, by creating a portfolio of different musical styles to demonstrate the capabilities of the software. A large database of recorded samples are classified into zones based upon the vibrational characteristics of the instruments, to model timbral variation in human percussive performance. The degree of timbral variation is governed by principles of biomechanics and human percussive performance. A fuzzy logic algorithm is applied to analyse current and first-order sample selection in order to formulate an ontological description of music performance variation. Asynchrony values were extracted from recorded performances of three different performance skill levels to create \timing fingerprints" which characterise unique features to each percussionist. The PD-103 uses real performance timing data to determine asynchrony values for each synthesised note. The spectral content of the sample database forms a three-dimensional loudness/timbre space, intersecting instrumental behaviour with music composition. The reparameterisation of the sample database, following the analysis of loudness, spectral flatness, and spectral centroid, provides an opportunity to explore the timbral variations inherent in percussion instruments, to creatively explore dimensions of timbre. The PD-103 was used to create a music portfolio exploring different rhythmic possibilities with a focus on meso-periodic rhythms common to parts of West Africa, jazz drumming, and electroacoustic music. The portfolio also includes new timbral percussive works based on spectral features and demonstrates the central aim of this thesis, which is the creation of a new compositional software tool that integrates human percussive performance and subsequently extends this model to different genres of music

Moving sounds and sonic moves : exploring interaction quality of embodied music mediation technologies through a user-centered perspective

This research project deals with the user-experience related to embodied music mediation technologies. More specifically, adoption and policy problems surrounding new media (art) are considered, which arise from the usability issues that to date pervade new interfaces for musical expression. Since the emergence of new wireless mediators and control devices for musical expression, there is an explicit aspiration of the creative industries and various research centers to embed such technologies into different areas of the cultural industries. The number of applications and their uses have exponentially increased over the last decade. Conversely, many of the applications to date still suffer from severe usability problems, which not only hinder the adoption by the cultural sector, but also make culture participants take a rather cautious, hesitant, or even downright negative stance towards these technologies. Therefore, this thesis takes a vantage point that is in part sociological in nature, yet has a link to cultural studies as well. It combines this with a musicological frame of reference to which it introduces empirical user-oriented approaches, predominantly taken from the field of human-computer-interaction studies. This interdisciplinary strategy is adopted to cope with the complex nature of digital embodied music controlling technologies. Within the Flanders cultural (and creative) industries, opportunities of systems affiliated with embodied interaction are created and examined. This constitutes an epistemological jigsaw that looks into 1) “which stakeholders require what various levels of involvement, what interactive means and what artistic possibilities?”, 2) “the way in which artistic aspirations, cultural prerequisites and operational necessities of (prospective) users can be defined?”, 3) “how functional, artistic and aesthetic requirements can be accommodated?”, and 4) “how quality of use and quality of experience can be achieved, quantified, evaluated and, eventually, improved?”. Within this multi-facetted problem, the eventual aim is to assess the applicability of the foresaid technology, both from a theoretically and empirically sound basis, and to facilitate widening and enhancing the adoption of said technologies. Methodologically, this is achieved by 1) applied experimentation, 2) interview techniques, 3) self-reporting and survey research, 4) usability evaluation of existing devices, and 5) human-computer interaction methods applied – and attuned – to the specific case of embodied music mediation technologies. Within that scope, concepts related to usability, flow, presence, goal assessment and game enjoyment are scrutinized and applied, and both task- and experience-oriented heuristics and metrics are developed and tested. In the first part, covering three chapters, the general context of the thesis is given. In the first chapter, an introduction to the topic is offered and the current problems are enumerated. In the second chapter, a broader theoretical background is presented of the concepts that underpin the project, namely 1) the paradigm of embodiment and its connection to musicology, 2) a state of the arts concerning new interfaces for musical expression, 3) an introduction into HCI-usability and its application domain in systematic musicology, 4) an insight into user-centered digital design procedures, and 5) the challenges brought about by e-culture and digitization for the cultural-creative industries. In the third chapter, the state of the arts concerning the available methodologies related to the thesis’ endeavor is discussed, a set of literature-based design guidelines are enumerated and from this a conceptual model is deduced which is gradually presented throughout the thesis, and fully deployed in the “SoundField”-project (as described in Chapter 9). The following chapters, contained in the second part of the thesis, give a quasi-chronological overview of how methodological concepts have been applied throughout the empirical case studies, aimed specifically at the exploration of the various aspects of the complex status quaestionis. In the fourth chapter, a series of application-based tests, predominantly revolving around interface evaluation, illustrate the complex relation between gestural interfaces and meaningful musical expression, advocating a more user-centered development approach to be adopted. In the fifth chapter, a multi-purpose questionnaire dubbed “What Moves You” is discussed, which aimed at creating a survey of the (prospective) end-users of embodied music mediation technologies. Therefore, it primarily focused on cultural background, musical profile and preferences, views on embodied interaction, literacy of and attitudes towards new technology and participation in digital culture. In the sixth chapter, the ethnographical studies that accompanied the exhibition of two interactive art pieces, entitled "Heart as an Ocean" & "Lament", are discussed. In these studies, the use of interview and questionnaire methodologies together with the presentation and reception of interactive art pieces, are probed. In the seventh chapter, the development of the collaboratively controlled music-game “Sync-In-Team” is presented, in which interface evaluation, presence, game enjoyment and goal assessment are the pivotal topics. In the eighth chapter, two usability studies are considered, that were conducted on prototype systems/interfaces, namely a heuristic evaluation of the “Virtual String” and a usability metrics evaluation on the “Multi-Level Sonification Tool”. The findings of these two studies in conjunction with the exploratory studies performed in association with the interactive art pieces, finally gave rise to the “SoundField”-project, which is recounted in full throughout the ninth chapter. The integrated participatory design and evaluation method, presented in the conceptual model is fully applied over the course of the “SoundField”-project, in which technological opportunities and ecological validity and applicability are investigated through user-informed development of numerous use cases. The third and last part of the thesis renders the final conclusions of this research project. The tenth chapter sets out with an epilogue in which a brief overview is given on how the state of the arts has evolved since the end of the project (as the research ended in 2012, but the research field has obviously moved on), and attempts to consolidate the implications of the research studies with some of the realities of the Flemish cultural-creative industries. Chapter eleven continues by discussing the strengths and weaknesses of the conceptual model throughout the various stages of the project. Also, it comprises the evaluation of the hypotheses, how the assumptions that were made held up, and how the research questions eventually could be assessed. Finally, the twelfth and last chapter concludes with the most important findings of the project. Also, it discusses some of the implications on cultural production, artistic research policy and offers an outlook on future research beyond the scope of the “SoundField” project

Computed fingertip touch for the instrumental control of musical sound with an excursion on the computed retinal afterimage

In this thesis, we present an articulated, empirical view on what human music making is, and on how this fundamentally relates to computation. The experimental evidence which we obtained seems to indicate that this view can be used as a tool, to systematically generate models, hypotheses and new technologies that enable an ever more complete answer to the fundamental question as to what forms of instrumental control of musical sound are possible to implement. This also entails the development of two novel transducer technologies for computed fingertip touch: The cyclotactor (CT) system, which provides fingerpad-orthogonal force output while tracking surface-orthogonal fingertip movement; and the kinetic surface friction transducer (KSFT) system, which provides fingerpad-parallel force output while tracking surface-parallel fingertip movement. In addition to the main research, the thesis also contains two research excursions, which are due to the nature of the Ph.D. position. The first excursion shows how repeated and varying pressing movements on the already held-down key of a computer keyboard can be used both to simplify existing user interactions and to implement new ones, that allow the rapid yet detailed navigation of multiple possible interaction outcomes. The second excursion shows that automated computational techniques can display shape specifically in the retinal afterimage, a well-known effect in the human visual system.Computer Systems, Imagery and Medi