Extending Interactive Aural Analysis: Acousmatic Music

This paper describes a new stage in the development of an ‘interactive aural’ approach to the analysis of electroacoustic music. I originally developed Interactive Aural Analysis in studying Jonathan Harvey’s Mortuos Plango, Vivos Voco. The approach uses software to enable the listener to engage aurally with the structure of the work and with the processes and sound materials used in its composition. The interactive software includes, for example, an aural paradigmatic analysis of the work, opportunities aurally and interactively to investigate the sound materials used by the composer, and interactive exercises using accurate emulations of the techniques employed in the work. It provides a way of understanding our heritage more deeply and exploring what we might learn for the future. Both the approach and the resulting analysis, comprising text and software (in Analytical Methods of Electroacoustic Music, ed. M. Simoni, Routledge, 2006), have been well received. My description of the approach can be found in the Proceedings of the 2005 International Computer Music Conference (pp. 85-8). This approach is now being extended to other works and the works chosen for analysis have been specifically selected to help broaden the scope of the interactive aural approach. Mortuos Plango takes recorded ‘musical’ sounds and analyses these sounds to obtain data which then forms the basis for the sound transformations and structure of the whole work. It is a highly successful work but this is not, of course, the only way to approach electroacoustic composition. The types of sound, the analytical approach to these sounds and the structural planning (in many ways reminiscent of Stockhausen) contrast strikingly with the approaches taken, for example, by composers in the acousmatic tradition in which the sounds used are often not traditionally ‘musical’ and the approach taken to these sounds is usually empirical and pragmatic rather than analytical, with the structure derived from spectromorphological principles. Developing an interactive aural analysis of such works therefore requires an expansion of interactive aural analysis conceptually and in terms of software tools. The analytical approach is also being further expanded in a different direction through the analysis of music combining live acoustic performance with real-time computer processing. This presentation however focuses on the issues raised and the solutions proposed in relation to an acousmatic work: Denis Smalley’s Wind Chimes. The new features include the following: Printed sonograms are a feature of many analyses of electroacoustic music. Although they have uses in certain circumstances they do have significant limitations in terms of what they show and how they relate to aural experience (as I have discussed previously, for example in my presentation at EMS07). However, a sonogram that can be manipulated and heard in the context of interactive aural analysis software has many advantages over a purely visual, static printed sonogram. As part of this project an interactive aural sonogram is being incorporated into the MSP-based software accompanying the musical analysis. This allows the user to focus in on particular aspects of the sound, isolating time and frequency regions and comparing these with similar occurrences elsewhere in the work. Selected gestures or passages can also be saved and placed in interactive aural paradigmatic charts or genealogical trees to elucidate the structure of the work or the development of material. Software is also being developed (using analysis data in SDIF files) to examine and compare aspects of the spectromorphology of sounds. This presentation will demonstrate some of the tools being developed and discuss more generally issues arising in the development of interactive aural analysis for acousmatic music

Regularity for Lorentz Metrics under Curvature Bounds

Let (M, g) be an (n+1) dimensional space-time, with bounded curvature with respect to a bounded framing. If (M, g) is vacuum or satisfies a mild condition on the stress-energy tensor, then we show that (M, g) locally admits coordinate systems in which the Lorentz metric is well-controlled in the (space-time) Sobolev space L^{2,p}, for any finite p.Comment: 18p

Introducing TaCEM and the TIAALS software.

This paper introduces the TaCEM project (Technology and Creativity in Electroacoustic Music), funded for 30 months by the Arts and Humanities Research Council in the UK, investigating the relationship between technological innovation and creative practice in electroacoustic music of the last 40 years (http://www.hud.ac.uk/research/researchcentres/tacem/). It is a collaborative project between the universities of Huddersfield and Durham in the UK and outputs from the project will include a book and freely available interactive software. This paper explains the context for the project and its goals, and discusses some of the generic software that is being developed as part of the project, intended not only for use in the project itself but also to be freely available for others to use in the study of any electroacoustic work as appropriate

Barry Truax Riverrun (1986/2004), a case study from the TaCEM project, exploring new approaches to techniques of analysis and re-synthesis in the study of concert electroacoustic works

At last year’s EMS in Lisbon we introduced the TaCEM project (Technology and Creativity in Electroacoustic Music), a 30-month project funded by the UK’s Arts and Humanities Research Council, and demonstrated the generic TIAALS software being produced as part of this project. This year we present an update on the project, focusing particularly on the first of our case studies, Barry Truax’s Riverrun. Eight works have been selected for the project, taking into account criteria such as historical context, the nature of the synthesis techniques employed, and the aesthetics that have underpinned their realisation. Key considerations have included the accessibility of the technical resources and composing materials used in their production, and opportunities to pursue particular lines of enquiry with the composer concerned. In selecting the eight works for detailed study, a further consideration has been the extent to which the composers explored techniques that were already available at the time in ways that are unique and distinctive, or alternatively developed entirely new methods of synthesis in pursuit of their creative goals. The pioneering work of Barry Truax in terms of developing techniques of granular synthesis assign his achievements almost exclusively to the latter classification, and the composition of Riverrun (1986/2004) is a landmark achievement in this regard. Truax’s composing environment evolved from the early study of interactive real-time synthesis techniques at the Institute of Sonology, Utrecht 1971-73, exploring the possibilities of using Poisson-ordered distributions in the generation of microsound, to the emergence of entirely granular techniques at Simon Fraser University, British Columbia a decade later, culminating in the development of his program GSX designed specifically for waveform-based synthesis and first used to compose Riverrun, and its later extension, GSAMX, that extended these granular techniques to include the manipulation of previously sampled sound material. At the time of composition conventional minicomputers still lacked the capacity to generate multiple voices of granulated sound material in real time, but for Truax the acquisition in 1982 of a high speed bit slice array processor, the DMX-1000, provided the enhancedprocessing power necessary for achieving such a goal. The unique characteristics of its special hardware and associated programming environment, managed in turn via a host PDP 11/23 computer, both empowered his creative objectives and also materially shaped and influenced the ways in which they could be practically achieved. The significance of such causal relationships in the evolution of the electroacoustic music repertory has yet to be widely understood, and this study of Riverrun corroborates the importance of such a line of investigation. In this case it has been possible to carry out a detailed study of the original system, still maintained in working order by Truax, leading to a reconstruction of key elements of Riverrun using a Max-based simulation of GSX, the authenticity of the results being assessed both subjectively by means of a direct aural comparison and also measured objectively using software. Our presentation at this year’s EMS in Berlin included a demonstration of examples of the software we have developed to enable readers to engage with Riverrun interactively, both by analysing the original recordings and by using our emulation of the GSX system to be able to recreate passages of the work and manipulate the techniques employed in order to learn more about them. We also gave examples of other materials we have collected in relation to this case study, including videos of the composer himself working with the GSX system and discussing the composition of Riverrun