Acousmatic music is not generally considered to be a particularly `rhythmic' form of music. In fact, quite the opposite: much acousmatic music generally avoids established rhythm, pulse or beat, in much the same way that it often eschews open melodic or, especially, harmonic structures. To what extent, varies significantly between composers and works; however, it is fair to say that, as a general rule, acousmatic music employs a sufficient degree of abstraction with regards to more `traditional' musical parameters, rhythm included, to make it an unlikely subject for a discussion of rhythm.
We will propose here, however, that despite the initial appearance of a lack of rhythm, acousmatic music does indeed contain rhythmic qualities, and that, in fact, rhythm is one of the dominating forces of acousmatic music.
The general attitude to rhythm across musique concrète and acousmatic music is one that is shared across much of electroacoustic practice, and indeed much of contemporary music more generally: a general sense of abstraction with regards to the more regimented, grid-like structures of traditional tonal music. `Rhythm' is often equated with `metered pulse'; as the latter is often eschewed by contemporary music, including acousmatic music, this is often assumed to mean an absence of rhythm. This is, however, critically and categorically false: there are many other very significant aspects of rhythm, beyond the simple quality of metre, and these aspects are often central to much contemporary music, and certainly to acousmatic music. To turn to Stockhausen: ``Although many of the new compositions have been criticized for their alleged `lack of rhythm', they may actually be considered to have `pure rhythm' without meter.'' (Stockhausen 1962: 43) While we will not attempt to address the relative `purity' of unmetered rhythm, we will argue that our reception of such rhythm is key to our experience of acousmatic music.
The most important key to acousmatic rhythm, however, does not lie here, in the fluid temporal attitudes to rhythm employed in some areas of contemporary instrumental musical; it lies, rather, as with much of acousmatic philosophy, in the rhythmic qualities of the world around us — or, perhaps more accurately, in our perception of the world around us.
Acousmatic composers have likely all had the experience of moving sonic materials around on a timeline in order to arrange them into sound objects or into longer phrases, only to find that, despite our firm compositional conviction that these materials are well suited to join together to form a compound unit, they are instead stubbornly refusing to fuse, to lose their discrete identities and become one. We might also recognise the related experience of placing phrases in a formal sequence, seeking the appropriate placements and spaces between that will make it all seem natural, only to find that these magical placements and relationship are proving furtive or elusive. In many of these cases, when the materials finally do lock together, or when the perfect durations of pauses between phrases are found, it is often extremely small differences in placement or duration that make the difference between a haphazard collection of sonic scraps, and a gracefully and invisibly fused gesture or phrase, or a graceful ballet from phrase to phrase.
The source of this almost mystical fusion, so painfully elusive at times, is compound, and therefore difficult to pin down with any degree of objectivity. In broad terms, it seems to be the result of a combination of two elements: our embodied sense of real-world gesture, and our culturally-learned sense of rhythm. If either of these is contradicted by the placements and timings of the sound object, gesture, phrase, or formal section we are attempting to craft, then these elements refuse to `come together'; when, at last, the elements align with our senses of rhythm and of embodied gesture, then they suddenly appear `natural' and `right', and all previous tensions between said materials tend to vanish. David Huron ascribes this to the relative degree of predictability in the timing of the event, a quality that may well be a question of musical rhythm, but may also be a question of embodiment, or, indeed, of anything that grants us a particular expectation based on familiarity (Huron 2008: 177-199).
Very importantly, however, it could be argued that `embodied gesture' and `musical rhythm' are not, in fact, two distinct qualities, but rather are two sides of exactly the same coin. For example, we might turn to the range of time scales in music proposed by Curtis Roads, beginning with the broadest scale (at its most extreme), and zooming increasingly closer, to arrive at the smallest subdivisions: 1) Infinite; 2) Supra; 3) Macro; 4) Meso; 5) Sound Object; 6) Micro; 7) Sample; 8) Subsample; 9) Infinitesimal (Roads 2001: 3-4). It could be argued that `gesture' and what is normally referred to as `rhythm' are simply different steps in Roads' categorization above — for example, we might equate `rhythm' with Roads' `Micro' level, and `gesture' with Roads' `Meso' level.
More importantly, however, research and theory in a number of fields — such as ecological psychology (Clarke 2005, Windsor 1995) and music cognition (Huron 2008) — suggest that musical notions such as `rhythm' are, in fact, simply cultural expressions of our embodied experience of ourselves and of the world, rooted in primal and innately `rhythmical' bodily acts such as walking, breathing, our heartbeat, etc. R. Murray Schafer (1977) extends this intuitive sense of rhythm out into the soundscape, linking our concept of musical rhythm to both our biological rhythms of heartbeat and footstep and the diurnal rhythms of the ecosystem. Gilles Gobeil echoes and extends this somewhat, to propose that the world itself is inherently rhythmical, with sounding events aligned or in rhythmical correspondence to an alarming degree. (Gobeil, personal correspondence) For Gobeil, acousmatic music is rhythmic in nature because the world is rhythmic in nature, a sentiment which echoes Schaeffer's foundational phenomenology, but with a somewhat Platonic twist where Gobeil posits acousmatic composition as an aesthetic shadow or reflection of the world itself. An interesting expression of Gobeil's attitude towards acousmatic rhythm is his tendency to `conduct' during acousmatic listening, including works that contain no immediately recognisable traces of metre, period, or other obviously `rhythmical' properties. It is remarkable to observe the degree and precision to which Gobeil is able to immediately, almost intuitively, identify with astonishing accuracy underlying rhythmical organisations which remained completely invisible to other listeners, including the composers themselves.
To some extent, these rhythmic qualities of the world described by Gobeil and Schafer may rather be a question of our perception and our cognition being rhythmically `primed': that we are tuned to scan the world for rhythmical qualities, possibly due to qualities of human speech and other forms of communication, or simply as a consequence of pattern-seeking (Berlyne 1971, Thaut 2005). On the other hand, it is possible that it is not only that we are looking for rhythm, but that our perceptual means are themselves inherently rhythmical, and that as a result all information coming in is filtered through and charged with this inherent rhythmical quality. In other words, the fact that we find rhythm everywhere is perhaps not so much a characteristic of our environment, but rather a consequence of rhythmical characteristics of our means of perception. (Mauro 2006)
In addition to the perspectives above, this paper will consider the works of several composers and theorists as case studies, and will further argue that canonical approaches to rhythm in western music, for example Lerdahl and Jackendoff (1983), are perhaps not as incompatible with acousmatic music as might first appear.