This paper outlines some recent developments in multichannel composition at the Electroacoustic Music Studios, University of Birmingham and its performance wing, BEAST (Birmingham ElectroAcoustic Sound Theatre). In doing so it attempts to codify and define some emerging aspects of spatialisation practice which are found both within the BEAST community and beyond. The discussion covers software and techniques developed and adapted for use with BEAST, new and pragmatic approaches to composing for large-scale multichannel systems, such as n-channel composition and composing in ‘stems’, and issues arising from a resulting blurring between composition and performance practices.

The key question posed here is how listeners experience meaning when listening to electroacoustic music, especially how they experience it as art. This question is addressed by connecting electroacoustic listening with the ways that the mind constructs meaning in everyday life. Initially, the topic of the everyday mind provides a framework for discussing cognitive schemas, mental spaces, the Event schema and auditory gist. Then, specific idioms of electroacoustic music that give rise to artistic meaning are examined. These include the creative binding of circumstances with events and the conceptual blending that creates metaphorical meaning. Finally, the listener’s experience of long-term events is discussed is relation to the location event-structure metaphor.

This article examines the use of Complexity Theory as an inspiration for the creation of new musical works, and highlights problems and possible solutions associated with its application as a compositional tool. In particular it explores how the philosophy behind Complexity Theory affects notions of process-based composition, indeterminacy in music and the performer/listener/environment relationship, culminating in providing a basis for the understanding of music creation as an active process within a context. The author presents one of his own sound installations, Cross-Pollination, as an example of a composition inspired and best understood from the philosophical position as described in Complexity Theory.

Approaches to the multichannel spatialisation of electroacoustic music are described here with reference to musical case studies which focus upon the expressive functions of space and the theatricality of sound diffusion in an acousmatic context. A site-specific approach to spatialisation is proposed to enhance theatrical aspects of musical performance. Case studies include proposals for novel layouts of the diffusion system within the performance space and compositional techniques that are designed to re-evaluate our understanding of individual listening spaces.

This paper describes a new sound spatialisation system which is an integral part of Rensselaer Polytechnic Institute’s new Experimental Media and Performing Arts Center (EMPAC). The Cinematic Spatial Sound Display (CSSD) was originally conceived for interactive panorama video installations, but the architecture goes beyond this particular application. The CSSD is characterised by its scalability to various loudspeaker configurations. It spatialises sound from dry sound files or live sources using control data that describe the spatial scenes. The time lines for source positions and other experimental parameters can be stored and edited in the CSSD, and the system can also process live user input to control selected parameters. The CSSD is more than just a sound positioning tool, and the underlying Virtual Microphone Control (ViMiC) technology was developed to support artists in designing new forms of spatial imagery. The software enables the user to create computer-generated rooms with virtual microphones and sound sources. The algorithm uses physical laws to auralise acoustic scenes – allowing realistic effects such as the Doppler shift and the simulation of various classical microphone techniques. Various parameters of ViMiC can be adjusted in real time, including the directivity patterns and orientations of both the microphones and sound sources as well as their precise locations. Surreal scenes can be created by assigning artificial directivity patterns to microphones or changing the laws of physics in the model. An algorithm to extract the sound-source positions in recordings using a microphone array is also part of the CSSD. The algorithm was specifically designed to operate in multiple sound-source scenarios and can also be used for telematic music applications.

A computational analysis of temporal patterns of acoustic intensity is applied to a series of recorded electroacoustic works in order to discern whether there are recurrent patterns in the intensity rise–fall structure. The works range from 1962 (Xenakis) to 2001 (Normandeau), and include composition and improvisation, large-scale (>25 minutes) and small-scale (<2 minutes) pieces, and acoustic, electronic and manipulated and synthesised sound. Contrary to Huron’s 1991 finding of long and gradual crescendi compared to short and abrupt decrescendi in classical music notation, it is found that in successive rise–fall events the rise phase (crescendo) is commonly shorter than the fall, and has a greater absolute rate of change of intensity than the fall. Correspondingly, crescendi occupy a smaller portion of the piece than decrescendi. When categorised into dynamic steps (such as p, mp, mf etc.), crescendi are usually less numerous than decrescendi. The results are considered from a cognitive point of view, in that this structuring may influence and thus result from listener attention and arousal patterns; and from a creator/performer point of view, in that embodied or virtualised effort may be key to the impact of an electroacoustic piece.

In this article we describe our ongoing research and development efforts towards integrating the control of sound spatialisation in computer-aided composition. Most commonly, the process of sound spatialisation is separated from the world of symbolic computation. We propose a model in which spatial sound rendering is regarded as a subset of sound synthesis, and spatial parameters are treated as abstract musical materials within a global compositional framework. The library OMPrisma is presented, which implements a generic system for the control of spatial sound synthesis in the computer-aided composition environment OpenMusic.

A comparison is made between two systems of real-time sample selection using timbral proximity that has relevance for live performance. Sound files in large sample libraries are analysed for audio features (amplitude RMS, spectral centroid, spectral flatness, and spectral energy using a Bark auditory modeller), and this data is statistically analysed and stored. Two methods of organisation are described: the first uses fuzzy logic to rate sample similarity, the second uses a self-organising map. The benefits and detriments of each method are described.

This article presents some musical and technical considerations on the handling of space in multichannel electroacoustic composition, making reference to three of my eight-channel acousmatic works: Percursos Enredados, Maresia and Sons Adentro.1 It comments on some relevant bibliography on the topic, outlining the main notions of space that informed the approach taken in the works. It also highlights how the spatial dimension of the sounds was enhanced and explored through Max/MSP patches that were used for processing the sound materials of the compositions. Finally, the article suggests some possible developments on this subject for the future.

This paper explores the dangers of electroacoustic instruments being lost, from the orphaning of compositions to technological innovations in the field going unnoticed, and presents a case for developing a knowledge base as part of an effort to address these issues. Building in particular on the work of Davies and projects such as EARS, ARiADA and SARA, it explains how taxonomical (hierarchical classification systems) and ontological (more general and in-depth methods for formally collecting information on a domain) approaches should be deployed in this work and outlines some emerging ideas that should be considered when taxonomies and ontologies are developed.