The notion of interactivity is likely to be a major aspect in the future of discussion of music technology. In a world of realtime computing, how composers, performers and other artists communicate with technology and their audiences will be an issue which could fundamentally change our approach to music making.

This paper describes a software package developed in MAX for using the gestures of a performer as control factors for music, via Buchla's ‘Lightning’. The software not only tracks the x and y coordinates of each transmitter, but also calculates the direction, speed and acceleration of their movements in the whole space and relative to each other. The program is very configurable, allowing calibration of the data evaluation and adjustment of the sampling rate of the values sent by the Lightning. These features have been applied to composition in two different areas: an interactive choreographic environment, and a performing interface for musicians.

This paper offers a critique of what are seen as key issues which are problematised within the field of interactive dance, centring on the role of the various artists and technologies involved in the development of interactive dance systems, the notion of interactivity versus non-interactivity, and the influence of traditional single art-form practices. The paper proposes that it is only through identifying the particular motifs promoted by the technology itself that a way forward can be found, and an interactive dance aesthetic can begin to emerge in earnest. The arguments presented in this paper are framed within the context of the authors' long-term work and collaboration within the area of interactive dance, and provides a detailed case study of the piece Lifting Bodies (1999).

In his work Contropasso (1998–9) Michelangelo Lupone collaborates with Massimo Moricone in the dance showcase piegapiaga achieving direct interaction between dancers and live electronics performance. The choreography takes advantage of acoustic events as generated by three dancers and further elaborated on via computer by the composer through use of granular algorithms and digital filtering, allowing the construction of the musical events to occur in real time. The live electronics performer changes sound parameters in relation to the dancers' movements by use of the program SDP – Sonorous Drawing Plane (S. Lanzalone) – created specifically for the control of different synthesis algorithms allowing them to be processed on systems such as Fly30 (CRM) and Mars (IRIS). SDP reads and converts computer mouse data as the operator creates lines corresponding to performance gestures, thus creating both visible and audible output. This software allows a single gesture to control more than one parameter, thus creating complex changes in the audio programme output. The article deals with different compositions, performances and didactic situations the author has experienced using SDP.

This article considers the notion of the invention as an instrumental concept in designing an interactive music system. The derivation of the idea is traced from Dreyfus' Bach and the Patterns of Invention. Issues of the nature of the interactive musical context are problematised on the basis of ideas from Adorno and Lyotard. The invention is presented as a mechanism for implementing the concepts of the embodiment and distribution of musical activity, which are shown to be generalisable. The relationship of composer and computer is considered in the light of a ‘prosthetic culture’. It is suggested that a crucial property of the invention is that of self-simulation.

The SndObj Sound Object Library is a C++ object-oriented audio processing framework and toolkit. This article initially examines some of the currently available sound processing packages, including sound compilers, programming libraries and toolkits. It reviews the processes involved in the use of these systems and their strengths and weaknesses. Some application examples are also provided. In this context, the SndObj library is presented and its components are discussed in detail. The article shows the library as composed of a set of classes that encapsulate all processes involved in synthesis, processing and IO operations. Programming examples are included to show some uses of the system. These, together with library binaries, source code and complete documentation, are included in the downloadable package, available on the Internet. Possible future developments and applications are considered. The library is demonstrated to provide a useful base for research and development of audio processing software.