This thesis is about interactive music, a musical experience that involves participation from the listener but is itself a composed piece of music and the Interactive Music Systems (IMSs) that create these experiences, such as a sound installation that responds to the movements of its audience. Some IMSs are brief marvels commanding only a few seconds of attention. Others engage those who participate for considerably longer. Our goal here is to understand why this difference arises and how we may then apply this understanding to create better interactive music experiences. I present a refined perspective of interactive music as an exploration into the relationship between action and sound. Reasoning about IMSs in terms of how they are subjectively perceived by a participant, I argue that fundamental to creating a captivating interactive music is the evolving cognitive process of making sense of a system through interaction. I present two new theoretical tools that provide complementary contributions to our understanding of this process. The first, the Emerging Structures model, analyses how a participant's evolving understanding of a system's behaviour engages and motivates continued involvement. The second, a framework of Perceived Agency, refines the notion of `creative control' to provide a better understanding of how the norms of music establish expectations of how skill will be demonstrated. I develop and test these tools through three practical projects: a wearable musical instrument for dancers created in collaboration with an artist, a controlled user study investigating the effects of constraining the functionality of a screen-based IMS, and an interactive sound installation that may only be explored through coordinated movement with another participant. This final work is evaluated formally through discourse analysis. Finally, I show how these tools may inform our understanding of an oft-cited goal within the field: conversational interaction with an interactive music system.

This thesis focuses on the design and evaluation of interactive music systems that enable non-experts to experience collaborative music-making in public set- tings, such as museums, galleries and festivals. Although there has been previous research into music systems for non-experts, there is very limited research on how participants engage with collaborative music environments in public set- tings. Informed by a detailed assessment of related research, an interactive, multi-person music system is developed, which serves as a vehicle to conduct practice-based research in real-world settings. A central focus of the design is supporting each player's individual sense of control, in order to examine how this relates to their overall playing experience. Drawing on approaches from Human-Computer Interaction (HCI) and interac- tive art research, a series of user studies is conducted in public settings such as art exhibitions and festivals. Taking into account that the user experience and social dynamics around such new forms of interaction are considerably in u- enced by the context of use, this systematic assessment in real-world contexts contributes to a richer understanding of how people interact and behave in such new creative spaces. This research makes a number of contributions to the elds of HCI, interactive art and New Interfaces for Musical Expression (NIME). It provides a set of de- sign implications to aid designers of future collaborative music systems. These are based on a number of empirical ndings that describe and explain aspects of audience behaviour, engagement and mutual interaction around public, in- teractive multi-person systems. It provides empirical evidence that there is a correlation between participants' perceived level of control and their sense of cre- ative participation and enjoyment. This thesis also develops and demonstrates the application of a mixed-method approach for studying technology-mediated collaborative creativity with live audiences.

Est-il possible de tester automatiquement le comportement temporisé des systèmes interactifs temps réel ? Ces travaux proposent une solution en fournissant un ensemble d’outils de test basé sur modèles pour Systèmes Musicaux Interactifs (SMI). Les SMIs doivent calculer et réagir pendant une performance musicale et ainsi accompagner les musiciens. Certains de ces SMIs peuvent être basés sur partition et doivent, dans ce cas, suivre à tout prix les contraintes temporelles imposées par le document haut-niveau appelé partition. En somme, pendant une performance, le système doit réagir en temps réel aux signaux audio venant des musiciens en suivant cette partition. Ceci demande au système une forte fiabilité temporelle et une robustesse face aux erreurs pouvant arriver en entrée du système. Hors, la vérification formelle de propriétés, comme la fiabilité temporelle avant l’exécution du système lors d’une performance, est insuffisamment traitée par la communauté de l’informatique musicale. Nous présentons dans cette thèse, la réalisation d’un ensemble d’outils de test basé sur modèles appliqué à un SMI. Il est à noter que ces outils de test ont été définis formellement dans le but de tester plus généralement le comportement temporelle des systèmes interactifs temps réel prenant en compte des évènements discrets et des durées définissables sur des échelles multiples. Pour ce résumé nous présentons rapidement l’état de l’art de nos travaux avant d’introduire la définition de notre modèle créé pour spécifier les aspects évènementiel («event-triggerred») et temporel («timed-driven») des SMIs. Ce modèle a la particularité d’être automatiquement construit depuis les conditions temporelles définies dans un document haut-niveau et peut être traduit vers un réseau d’Automates Temporisés (TA). Dans le cadre de la performance musique mixte électronique/instrumentale nous avons introduit une notion de durée multi-temps gérée par notre modèle et une génération de trace d’entrée musicalement pertinente par notre ensemble d’outils de test. Pour tester un SMI selon les différentes attentes de l’utilisateur, notre ensemble d’outils a été implémenté avec plusieurs options possibles. Parmi ces options, la possibilité de tester automatiquement, selon une approche différée ou temps réel, la conformité temporelle du SMI est proposée. En effet, l’approche différée utilise des outils de la gamme du logiciel Uppaal [44] pour générer une suite de traces d’entrées exhaustive et garantir la conformité temporelle du système testé. Il est également possible de tester une trace d’entrée particulière ou une version altérée («fuzzed») de la trace idéale définie par la partition. L’approche temps réel interprète quand-à elle directement le modèle comme des instructions de byte-code grâce à une machine virtuelle. Finalement, des expériences ont été conduites via une étude de cas sur le suiveur de partition Antescofo. Ces expériences ont permis de tester ce système et d’évaluer notre ensemble d’outils et ses différentes options. Ce cas d’étude applique nos outils de test sur Antescofo avec succès et a permit d’identifier des bogues parfois non triviaux dans ce SMI. / Can real-time interactive systems be automatically timed tested ? This work proposes an answer to this question by providing a formal model based testing framework for Interactive Music Systems (IMS). IMSs should musically perform computations during live performances, accompanying and acting like real musicians. They can be score-based, and in this case must follow at all cost the timed high-level requirement given beforehand, called score. During performance, the system must react in real-time to audio signals from musicians according to this score. Such goals imply strong needs of temporal reliability and robustness to unforeseen errors in input. Be able to formally check this robustness before execution is a problem insufficiently addressed by the computer music community. We present, in this document, the concrete application of a Model-Based Testing (MBT) framework to a state-of-the-art IMS. The framework was defined on purpose of testing real-time interactive systems in general. We formally define the model in which our method is based. This model is automatically constructed from the high-level requirements and can be translated into a network of time automata. The mixed music environment implies the management of a multi-timed context and the generation of musically relevant input data through the testing framework. Therefore, this framework is both time-based, permitting durations related to different time units, and event-driven, following the musician events given in input. In order to test the IMS against the user’s requirements, multiple options are provided by our framework. Among these options, two approaches, offline and online, are possible to assess the system timed conformance fully automatically, from the requirement to the verdict. The offline approach, using the model-checker Uppaal, can generate a covering input suite and guarantee the system time reliability, or only check its behavior for a specific or fuzzed input sequence. The online approach, directly interprets the model as byte-code instructions thanks to a virtual machine. Finally, we perform experiments on a real-case study: the score follower Antescofo. These experiments test the system with a benchmark of scores and a real mixed-score given as input requirements in our framework. The results permit to compare the different options and scenarios in order to evaluate the framework. The application of our fully automatic framework to real mixed scores used in concerts have permitted to identify bugs in the target IMS.

Multiple taxonomies and typologies related to interactive music systems have been made, focusing on improvisation, music generation and software based music agents. These studies are comprehensive but general in their analysis of the generated output and music interaction, lacking an in-depth consideration of rhythm. Based on relevant literature on rhythm perception, principles of music performance and interactive music systems, this thesis conceptualizes rhythm according to seven rhythm dimensions, and surveys the state-of-theart of interactive music systems. It considers eighteen interactive music systems affording music input and rhythm generation. These systems are analyzed and categorized according to a rhythm taxonomy extending on a prior taxonomy related to interactive music systems. Analyzing the data reveals dimensions of rhythm that need deeper considerations, which, in comparison with the conclusions of the prior taxonomy, results in design considerations and evaluation methods for the design of rhythmic generation and rhythmic interaction of future interactive music systems. / Det existerar ett flertal taxonomier och typologier relaterade till interaktiva musiksystem, med fokus på improvisation, musikgenerering och mjukvarubaserade intelligenta musikagenter. Dessa studier är omfattande men allmänna i sin analys av musikinteraktionen och musiken som genereras av systemen och saknar en djupgående beaktande av rytm. Baserat på relevant litteratur om rytmuppfattning, principer för musikframförande och interaktiva musiksystem, konceptualiserar denna master uppsats rytm enligt sju rytmdimensioner och undersöker forskningsfältet för interaktiva musiksystem. Arton interaktiva musiksystem som möjliggör musikinmatning och rytmgenerering undersöks. Dessa system analyseras och kategoriseras enligt en rytm-taxonomi som bygger på en tidigare taxonomi relaterad till interaktiva musiksystem. Genom dataanalys framkommer det vilka rytmdimensioner som är i behov av ytterligare efterforskning, vilket i jämförelse med slutsatserna av den tidigare taxonomin resulterar i designöverväganden och utvärderingsmetoder för framtida utveckling av interaktiva musiksystem med fokus på rytm.