(40) L'espace composé dans l'acousmatique stéréophonique
(41) Dans l’acousmatique stéréophonique, l’espace composé peut être conçu comme le résultat d’un double processus par lequel les spectres sonores sont : (1) augmentés et manipulés au fil de leur évolution dans l’espace vertical bidimensionnel ; et (2) configurés et superposés dans l’espace tridimensionnel du champ stéréophonique du studio. Les dimensions verticales et tridimensionnelles des spectres sonores sont conçues comme les deux composantes du flux sonore de l’œuvre. La création d’espaces composés est donc centrale à la pratique compositionnelle de l’acousmatique en tant qu’elle permet au compositeur de façonner et de positionner les spectres sonores, qui proposent déjà des qualités tridimensionnelles intrinsèques, dans un champ stéréophonique tridimensionnel.
In the stereo acousmatic idiom, composed space can be understood as the result of a dual process whereby sound spectra are: (1) titrated and shaped as they evolve over time in vertical, bi-dimensional, space; and (2) are mapped and superimposed in three-dimensional space within a stereo field in the studio.[1] The vertical and three-dimensional spatial dimensions of sound spectra are considered as the two components of the sounding flow in the work. Creating composed space is thus central to the compositional effort in the acousmatic idiom insofar as it permits the composer to mould and position sound spectra, which exude intrinsic three-dimensional spatial qualities, onto a three-dimensional location in a stereo field. (41)
The following discussion, founded upon personal experience, illustrates how the creation of composed space in a stereo acousmatic work is fundamental to the compositional process. For example, if we listen to the stereo source recording of a foghorn at close range we can perceive a sonic profile that is loud, dense, static, and physically immobile. The composer may choose to leave these characteristics untouched and place the sound, as it is, in the stereo field in the work, where its elevated amplitude, opaque and unchanging spectral nature and three-dimensional immobility, can serve to mask other sound material. However, the composer may otherwise choose to accentuate or attenuate the higher or lower frequencies in the sound, cull its interior in such a way to create spectral grooves or ‘hollow out’ its interior entirely, and then retransform (e.g. re-filter or fragment) its residual spectrum. The composer may then attenuate the sound’s overall volume, which attenuates proximity, and precisely re-calibrate the sound’s amplitude envelope to enhance its new spectral character, or to create a sense of trajectory between the foreground and background of the stereo field. Finally, the composer may widen or narrow the sound’s original stereo image, or pan the sound so that it travels across the stereo axis. Thus, a massive, non-evolving source-sound can be reformulated to function as a translucent, scintillating veil in the middle-ground of the stereo field, or as a mobile, sylph-like form that darts or slides across the stereo axis anywhere between the foreground and background, plying either the spectral ceiling or floor of the work, or any zone in between.
(42) Le terme ‘espace composé’ correspond au concept d’espace interne, une des deux parties du discours de Chion sur l’espace dans les musiques de sons ‘fixés’. L’espace interne est similaire à l’espace composé en ce qu’il concerne aussi les dimensions spatiales d’une œuvre acousmatique qui sont enregistrées sur support et présentent des caractères tels que le relief sonore et la distribution d’éléments sonores sur différents canaux.
(43) Le contenu spatial composé d’une œuvre acousmatique est articulé en-dehors du studio, lors d’une interprétation publique, dans un espace d’écoute dont les conditions peuvent varier entre un système de monitoring stéréophonique dans une petite salle (illustré dans la Figure 4) et un système de diffusion large dans un grand espace de concert (comme c’est le cas pour l’acousmonium du Groupe de Recherches Musicales). Le mot ‘acousmonium’ est un terme et un concept défini par François Bayle en 1974.
The term ‘composed space’ corresponds to the term l’espace interne(‘internal space’), one part of Chion’s bifurcated discussion of space that addresses music comprising ‘fixed’ sounds. Internal space is analogous to composed space insofar as it also refers to the spatial dimensions within an acousmatic piece that are recorded onto supporting medium and are characterised by qualities such as sonic relief, and the distribution of sound elements on different channels (42) (Chion, 1991: 50).
The composed spatial content of an acousmatic work is articulated outside the studio, during public performance in a listening space, the diverse conditions of which can vary between a stereo monitoring system in a small room and an extensive diffusion system – such as the acousmonium at the Groupe de Recherches Musicales – in a large concert space. The word ‘acousmonium’ is both a term and concept defined by François Bayle in 1974 (43), which refers to
“[…] an ensemble of ‘sonic projectors’ that orchestrate an acoustic image. They comprise a series of multichannel ‘sonic screens’, varied in calibre, distances and directions, that aid the organisation of the acoustic space according to the characteristics of the concert hall, and the psychological space according to given attributes of the work” (Bayle, 1993: 183).[2]
(44) Le mot ‘espace d’écoute’ correspond au concept d’espace externe de Chion, qui concerne les paramètres physiques très variables liés aux conditions d’écoute en-dehors du studio ou de l’écoute sur casque.
The term ‘listening space’ corresponds to Chion’s term l’espace externe (‘external space’), which addresses the widely variable physical parameters of listening conditions outside studio or headphone use. (44) It can designate, for example, the acoustic profile of the listening space, the number, type and disposition of loudspeakers, the use of filters or equalisation during performance, and the type of sound diffusion employed (e.g. human interpretation or an automated diffusion system) (Chion, 1991: 50). Other factors play an important role in the ‘articulation’ of composed space in an external, listening space, notably the power and dimensions of the loudspeakers, as well as the proximity and angle of the loudspeakers in relation to the listener’s position. Hence, the listener apprehends the composed spatial content of the acousmatic work within the acoustic frame proposed by the listening space, which, as Smalley notes, “[…] theoretically encloses the composed space within it. Thus perceived, musical space is always a superimposed space” (Smalley, 1996: 91) (Smalley’s italics).
[1] I address the titration and shaping of sound spectra primarily during a separate stage of sound transformation, using the ‘making/listening’ method discussed in section 2.1 of my dissertation, before mapping and superimposing sounds in a stereo or multichannel environment. It is a sequential approach that embraces a wide variety of sound material for an acousmatic work. However, current technology allows the composer to address both compositional processes, using the ‘making/listening’ method, within one digital audio environment. This approach is integrated because it permits the composer to shape the spectral content of a sound in a specific three-dimensional location within the existing sonic context of the work.