The two preceding issues within Vol. 2 of Organised Sound have focused upon the time and frequency domains, so it is perhaps appropriate that we now consider the analysis–synthesis paradigm which inevitably unites them. More specifically, the analysis and synthesis theme brings together discussions of the time and frequency domains under the umbrella of professional musical practice within the musicological, compositional, performance or technological realms. It is a theme which is inextricably linked to the working practice of many within the field, and one which has particular resonance for musical work.

In this article, and within the context of sound art as a basis for artistic freedom in experimental music and art, the development of pendulum-based sculptural instruments and an improvisational form of video called ‘percussive video’ are described. Methods used to produce time-based public art events are also outlined, and their effectiveness in directing social change at the local level is discussed.

Working on Analogique B in the late 1950s, Xenakis formulated the ‘hypothesis of a second order sonority’. This paper focuses on this concept, and shows its crucial meaning in the composition of a number of pieces, such as Concret PH, Analogique B and the very recent Gendy3 and S709. The perspective taken is twofold: on one side, the problem of 2nd-order sonorities is seen as a problem in modelling perceptual attributes (or timbre) of sound in terms of ‘emergent properties of organised sound structure’. This is also related to the composer’s pioneering work with granular sound representations and nonstandard methods of sound synthesis. On the other, the issue is discussed in conjunction with Xenakis’ attempt at implementing thoroughly formalised ‘mechanisms’ or ‘systems’ based on the mathematics of stochastic processes. The paper shows that the issue touched on here is essential to the aesthetics of Xenakis’ electroacoustic music. It also questions whether the formalisation of stochastics is a suitable means to let 2nd-order sonorities emerge from the internal life of the sound matter. The limitations of Xenakis’ ‘mechanisms’ are described in terms of their cybernetics, and are situated in the context of artistic and scientific paradigm shifts concerning the relationship between order, disorder and chaos.

Sound modelling is an important part of the analysis–synthesis process since it combines sound processing and algorithmic synthesis within the same formalism. Its aim is to make sound simulators by synthesis methods based on signal models or physical models, the parameters of which are directly extracted from the analysis of natural sounds. In this article the successive steps for making such systems are described. These are numerical synthesis and sound generation methods, analysis of natural sounds, particularly time–frequency and time–scale (wavelet) representations, extraction of pertinent parameters, and the determination of the correspondence between these parameters and those corresponding to the synthesis models. Additive synthesis, nonlinear synthesis, and waveguide synthesis are discussed.

Analysis–resynthesis (A–R) systems gain their flexibility for creative transformation of sound by representing sound as a set of musically useful features. The analysis process extracts these features from the time domain signal by means of a time–frequency representation (TFR). The TFR provides an intermediate representation of sound that must make the features accessible and measurable to the rest of the analysis. Until very recently, the short-time Fourier transform (STFT) has been the obvious choice for time–frequency representation, despite its limitations in terms of resolution. Recent and ongoing developments are providing several alternative schemes that allow for a more considered choice of TFR. This paper reviews these contemporary approaches in comparison with the more classical ones and with reference to their applicability, merits and shortcomings for application to sound analysis. (Where they have been successfully applied, details are provided.) The techniques reviewed include linear, bilinear and higher-order spectra, nonparametric and parametric methods and some sound-model-specific TFRs.

The time–frequency representation (TFR) is the initial stage of analysis in sound/music analysis–resynthesis (A–R) systems. Given a time-domain waveform, the TFR makes temporal and spectral detail available to the remainder of the analysis, so that the component features may be extracted. The resulting ‘feature set’ must represent the sound as completely as the original time-domain signal, if the A–R system is to be capable of effective transformation and good synthesis sound quality. Therefore the system as a whole is reliant upon the TFR to make the sound components detectable, separable and measurable. Yet the standard TFR to-date is the short-time Fourier transform (STFT), of which the shortcomings, in terms of resolution, are well recognised. The purpose of this paper is to demonstrate the importance of the TFR to system function and system design. Poor feature extraction is shown to result from the use of inappropriate TFRs, whose underlying assumptions and expectations do not match those of the system. Existing models are used as case studies, with examples of performance for different sound types. A philosophy for A–R system design that includes TFR design is presented and a methodology for implementing it is proposed.

Evolution in musical notation has been tied to the development of music theory and performance.

This article presents a full analysis of Crosstalk – a piece for tape by Michael Vaughan (1989). The methodological approach employed here develops its concepts and techniques from those of Music Semiology and Spectromorphology. The former provides the concept and method of semiological neutral inference – as applied by Nattiez (1982, 1990). The latter – developed by Smalley (1986) – offers tools and a terminology for the characterisation of timbre and temporal functionality within the musical work.

Software packages developed for visualising time-varying timbres, finding parameter settings for modelling acoustic instrument tones, and for synthesising timbres are described. The sndan package, written in C for Unix machines, provides spectrum analysis, pitch tracking, spectrum display, parameter modification, and additive synthesis. Other programs that estimate the best possible parameters for recreating acoustic sounds using techniques such as multiple FM and wavetable synthesis and extended nonlinear/filter synthesis are outlined. Hybrid instruments created by fashioning sounds out of the recombined spectral characteristics of two or more very different tones are also presented.