This article examines differing approaches to the definition, classification and modelling of interactive music systems, drawing together both historical and contemporary practice. Concepts of shared control, collaboration and conversation metaphors, mapping, gestural control, system responsiveness and separation of interface from sound generator are discussed. The article explores the potential of interactive systems to facilitate the creation of dynamic compositional sonic architectures through performance and improvisation.

In this paper we reflect on the performer–instrument relationship by turning towards the thinking practices of the French philosopher Maurice Merleau-Ponty (1908–1961). Merleau-Ponty’s phenomenological idea of the body as being at the centre of the world highlights an embodied position in the world and bestows significance onto the body as a whole, onto the body as a lived body. In order to better understand this two-way relationship of instrument and performer, we introduce the notion of the performative layer, which emerges through strategies for dealing with discontinuities, breakdowns and the unexpected in network performance.

The use of a laptop computer for musical performance has become widespread in the electronic music community. It brings with it many issues pertaining to the communication of musical intent. Critics argue that performances of this nature fail to engage audiences because many performers use the mouse and/or computer keyboard to control their musical works, leaving no visual cues to guide the audience as to the correlation between performance gestures and musical outcomes. The author will argue that interfaces need to communicate something of their task and that cognitive affordances (Gibson 1979) associated with the performance interface become paramount if the musical outcomes are to be perceived as clearly tied to real-time performance gestures – in other words, that the audience are witnessing the creation of the music in that moment as distinct to the manipulation of pre-recorded or pre-sequenced events. Interfaces of his kind lend themselves particularly to electroacoustic and computer music performance where timbre, texture and morphology may be paramount.

Composers, musicians and computer scientists have begun to use software-based agents to create music and sound art in both linear and non-linear (non-predetermined form and/or content) idioms, with some robust approaches now drawing on various disciplines. This paper surveys recent work: agent technology is first introduced, a theoretical framework for its use in creating music/sound art works put forward, and an overview of common approaches then given. Identifying areas of neglect in recent research, a possible direction for further work is then briefly explored. Finally, a vision for a new hybrid model that integrates non-linear, generative, conversational and affective perspectives on interactivity is proposed.

This paper explores the differences in the design and performance of acoustic and new digital musical instruments, arguing that with the latter there is an increased encapsulation of musical theory. The point of departure is the phenomenology of musical instruments, which leads to the exploration of designed artefacts as extensions of human cognition – as scaffolding onto which we delegate parts of our cognitive processes. The paper succinctly emphasises the pronounced epistemic dimension of digital instruments when compared to acoustic instruments. Through the analysis of material epistemologies it is possible to describe the digital instrument as an epistemic tool: a designed tool with such a high degree of symbolic pertinence that it becomes a system of knowledge and thinking in its own terms. In conclusion, the paper rounds up the phenomenological and epistemological arguments, and points at issues in the design of digital musical instruments that are germane due to their strong aesthetic implications for musical culture.

In the majority of discussions surrounding the design of digital instruments and real-time performance systems, notions such as control and mapping are seen from a classical systems point of view: the former is often seen as a variable from an input device or perhaps some driving signal, while the latter is considered as the liaison between input and output parameters. At the same time there is a large body of research regarding gesture in performance that is concerned with the expressive and communicative nature of musical performance. While these views are certainly central to a conceptual understanding of ‘instrument’, it can be limiting to consider them a priori as the only proper model, and to mediate one’s conception of digital instrument design by fixed notions of control, mapping and gesture. As an example of an alternative way to view instrumental response, control structuring and mapping design, this paper discusses the concept of gesture from the point of view of the perception of human intentionality in sound and how one might consider this in interaction design.

Throughout the short history of interactive digital music, there have been frequent calls for a new language of interaction that incorporates and acknowledges the unique capabilities of the computational medium. In this paper we suggest that a conceptualisation of possible modes of performance–time interaction can only be sensibly approached in light of the ways that computers alter the social–artistic interactions that are precursive to performance. This conceptualisation hinges upon a consideration of the changing roles of composition, performer and instrument in contemporary practice. We introduce the term behavioural object to refer to software that has the capacity to act as the musical and social focus of interaction in digital systems. Whilst formative, this term points to a new framework for understanding the role of software in musical culture. We discuss the potential for behavioural objects to contribute actively to musical culture through two types of agency: performative agency and memetic agency.

Mobile phones offer an attractive platform for interactive music performance. We provide a theoretical analysis of the sensor capabilities via a design space and show concrete examples of how different sensors can facilitate interactive performance on these devices. These sensors include cameras, microphones, accelerometers, magnetometers and multitouch screens. The interactivity through sensors in turn informs aspects of live performance as well as composition though persistence, scoring, and mapping to musical notes or abstract sounds.

We present an experimental study on articulation in bowed strings that provides important elements for a discussion about sound synthesis control. The study focuses on bow acceleration profiles and transient noises, measured for different players for the bowing techniques detaché and martelé. We found that maximum of these profiles are not synchronous, and temporal shifts are dependent on the bowing techniques. These results allow us to bring out important mechanisms in sound and gesture articulation. In particular, the results reveal a potential shortcoming of mapping strategies using simple frame-by-frame data-stream procedures. We propose instead to consider input control data as time functions, and consider gesture co-articulation processes.

This article presents a theoretical framework for the design of expressive musical instruments, the Musical Interface Technology Design Space: MITDS. The activities of imagining, designing and building new musical instruments, performing, composing, and improvising with them, and analysing the whole process in an effort to better understand the interface, our physical and cognitive associations with it, and the relationship between performer, instrument and audience can only be seen as an ongoing iterative work-in-progress. It is long-term evolutionary research, as each generation of a new musical instrument requires inventiveness and years of dedication towards the practice and mastery of its performance system (comprising the interface, synthesis and the mappings between them). Many revisions of the system may be required in order to develop musical interface technologies that enable us to achieve truly expressive performances. The MITDS provides a conceptual framework for describing, analysing, designing and extending the interfaces, mappings, synthesis algorithms and performance techniques for interactive musical instruments. It provides designers with a theoretical base to draw upon when creating technologically advanced performance systems, and can be seen as a set of guidelines for analysis, and a taxonomy of design patterns for interactivity in musical instruments. The MITDS focuses mainly on human-centred design approaches to realtime control of the multidimensional parameter spaces in musical composition and performance, where the primary objective is to close the gap between human gestures and complex synthesis methods.