A Theoretical Framework for Electro-Acoustic Music

Developing a theoretical framework for electro-acoustic music presents an array of problems not present in the analysis of Western tonal and post-tonal music. We present a theoretical framework characterized by the interaction of a perceptual and an analytic model. The perception of a composition is used to inform the analytic model. The analytic model examines aspects of a composition ranging from macrostructures, such as form, to microstructures, such as the spectrum at a moment in time. The theoretical framework is exercised through the study of Late August by Paul Lansky. 1. A Brief Discussion of Analytic Methodologies for Western Tonal Music While intellectual speculation on music can be traced to antiquity, music analysis, as we now understand it, emerged in the eighteenth century [Bent & Drabkin, 1987]. Many of the central concerns of early theorists, including phrase structure and modeling of large formal design, remain central concerns in the analysis of music today. Just as issues of pitch and rhythm were paramount in the early days of music analysis, so too are they similarly privileged in the analysis of contemporary music. Traditional analyses often organize elements of pitch and rhythm hierarchically: motive, theme, phrase, phrase group, and section. Schenkerian approaches delineate foreground, middleground, and background levels. Attempts to directly apply traditional analytic methodologies to electro-acoustic music are problematic. While electro-acoustic and acoustic music share many musical attributes, these attributes function differently in each genre. How then are we to understand the formal organization of electro-acoustic music? Consider a musical phrase. As William Rothstein says, a phrase must contain Òdirected motion in time from one tonal entity to anotherÓ [Rothstein, 1989]. Since RothsteinÕs concept of a phrase is so deeply intertwined with tonal processes and thus not applicable to a great deal of electro-acoustic music, we instead think of a phrase as Roger Sessions put it, Òthe portion of music that must be performed, so to speak, without letting go, or figuratively, in a single breathÓ [Sessions, 1950]. Just as the notion of a musical phrase changes throughout history, so too must our understanding and analysis of musical structures. In this paper, we offer suggestions to some of the problems of analytic methodologies for electro-acoustic music. We combine our understanding of music theory with information gleaned from research in signal processing to develop an analytic framework for the analysis of electro-acoustic music. Through this marriage of music theory and signal processing, we are able to enhance our understanding of electro-acoustic music. 2. The Perceptual Model The analysis of music begins with the process of listening. Our perceptual model is centered upon the experiences of a listener in an ideal stereophonic listening environment (Fig. 1). The listener auditions the composition and discerns the musical elements of the composition. The process of identifying the musical elements in an electro-acoustic composition is borrowed from research in auditory scene analysis. Auditory scene analysis is the process whereby all the auditory evidence that comes over time, from a single environmental source, is assembled by the listener as a perceptual unit [Bregman, 1990]. Bregman observes that the auditory system apparently keeps an Ôopen slotÕ available for the return of a sound. His observation may be extended to the perception of music as evidenced by our tendency to listen for the return of previously stated musical events. In the case of auditory analysis of an electro-acoustic composition, these auditory streams may be any musical event such as pitch clusters, a timbre, or a class of timbres. Listener Left Channel Right Channel