can only apprehend music if they discover a perceptual
affinity with its materials and structure. Such an
affinity depends on the partnership between composer
and listener mediated by aural perception.... The
primacy of perception is unassailable since without
it musical experience does not exist. [Smalley, 1986]
significance of the electroacoustic medium is that,
like cinema, it is a medium of illusion. Composers have
available as raw material any sound (recorded, synthesised,
processed...) and therefore any illusion, so the basic
carriers of musical meaning are not confined to simple
parameters such as pitch and duration, but may be ambiguous
and difficult to identify. Structures may instead rely
purely on layers of association or recognition, or a
host of other parameters, easily comprehended, but not
usually associated with music. We are dealing with the
articulation of illusory objects in virtual space and
such illusory spaces and objects may be "real",
surreal or abstract.
Denis Smalley reminds us, the listener needs to know
what aspect of the musical material defines structure.
Whatever this might be, in electroacoustic music, as
with any other music, it is the function of performance
to communicate that structure in a particular space
at a particular time. I would like to propose that the
"gentle art" of sound diffusion should be
seen as a necessity rather than an option in the public
presentation of electroacoustic music, as it is only
through careful performance that such "carriers
of meaning" can be effectively communicated.
Pressing suggests [Pressing, 1994]
know that one of the reasons that listeners show limited
liking for contemporary art music is their inability
to code it either on the basis of simple pitch or
rhythmic structures, and hence assign it meaning"
the meaning in electroacoustic music often lies in other
parameters this is hardly surprising. He goes on to
suggest, however that:
we are making computer music "unphysical"
in failing to tap basic cognitive motor designs used
in human communication...Mainstream computer music
seems to harbour a resentment towards things dance-like
or motoric....[which] seems to stem from intellectual
positions that de-emphasise the importance of the
am not sure what music Pressing has in mind in his criticism
as this is simply not true of much electroacoustic music,
and I think it is key to our understanding of the music
that we realise that it very often does "tap basic
cognitive motor designs" in simple and direct ways.
However, if this is not in the rhythmic sense that Pressing
seems to be suggesting, what is the physical nature
of the experience of electroacoustic music?
would like to suggest that it is our listening experience
of the physical, sounding world which is key to our
understanding of both the illusory objects and virtual
space of electroacoustic music, and if the music appears
to be "unphysical" it is often the fault of
Wishart observes that when we hear a sound we infer
something about what physical action caused it - we
hear the difference between something being plucked,
scraped, struck and blown. And furthermore, we instinctively
try to infer such actions/causes even for sounds we
do not recognise, even those which may be completely
synthetic, or "unreal". And whilst we can
choose to ignore our everyday experience and suspend
the inference of "reality", we do so "in
the knowledge that this background exists." [Wishart,
Smalley, too, notes:
only do we listen to the music, but we also decode
the human activity behind the spectromorphologies
through which we automatically gain a wealth of psycho-physical
information.... [Smalley, unpublished]
calls this property
bonding...: the natural tendency to relate sounds
to supposed sources and causes, and to relate sounds
to each other because they appear to have shared or
proposes that these relationships hold for all musics.
Abstract, instrumental music is no exception and it
is not only the physical world which is significant
to our understanding:
listeners experience of listening to instruments
is a cultural conditioning process based on years
of (unconscious) audio-visual training.
knowledge of sounding gesture is .... culturally very
strongly embedded. This cannot be ignored and denied
when we come to electroacoustic music. It is particularly
important for acousmatic music where the sources and
causes of sound-making become remote or detached from
known, directly experienced physical gesture and sounding
it is not only the perceived source object and cause
which are significant
in mixed work [works for tape with instruments] the
perceived behavioural relationships between the visible,
gesture-bearing performer and the surrounding acousmatic
context will be crucial to the works understanding....
Spatial perception is inexorably bound up with spectromorphological
content.....[and] Space, heard through spectromorphology,
becomes a new type of "source" bonding.
Wishart uses the term "landscape" to describe
the "virtual acoustic space" which is the
imagined source of the sounds we hear, and describes
four types of landscape based on the combinations of
real and unreal, objects and spaces.
these writers have in common is a perception of the
materials of electroacoustic music based on patterns
of human perception which extends beyond traditional
musical parametrisation, allowing an overview across
the range of possibilities and suggesting a model of
how these diverse materials can generate musical meaning.
Most significantly they suggest that we instinctively
try to make sense of a (new) sound by attributing a
source object with an associated action or cause, that
we interpret its perceived location and spatial behaviour,
and that or responses are based on our instincts and
how does this recognition of our subconscious understanding
of this material help us? In what ways do imaginary
objects in virtual space articulate musical structure?
Young suggests that our instinctive response along a
"reality-abstraction continuum" becomes a
powerful tool for structural interpretation of a work.
In addition to the implied source,
is a measure of the psychological distance between
a sound which displays a source-cause ambiguity and
a surmised source-cause model. [Young, 1994]
goes on to propose "juxtaposition and mediation"
as structural tools:
soon as sounds are articulated in a tangible three-dimensional
spatial field, an important aspect of environmental
reality has [to] be analogised...... Although [a] sound
itself ...[may not be]... specifically from a particular
environmental or cultural source, it [may] nevertheless
serve to define a "realistic" acoustic space
and behave as though it were a physical entity... [Young,
it is in perceiving the distances (physical, psychological
etc., analogous, say, to harmonic distance in tonal
music) that we infer structure.
too, discusses the creative possibilities of using "landscapes"
for making structure.
acoustic space which we represent need not be real
and we may in fact play with the listeners perception
of landscape. This aspect of sonic architecture was
not an aspect of the traditional craft of the musician.....It
is therefore easy to dismiss it by linking it with
the somewhat cruder and culturally circumscribed procedures
of associationism (programme music) and mimicry which
exist as a somewhat marginal aspect of ... Western
art music. This, however, would be foolish... Not
only does the control and composition of landscape
open up large new areas of artistic exploration and
expression, in the sphere of electroacoustic music,
[but] it will enter into the listeners perception
of a work regardless of the composers indifference
to it. [Wishart, 1985]
last sentence is critically important. What Wishart
is suggesting is that the nature of the (electroacoustic)
medium fashions our listening response whether the composer
likes it or not.
we noted above sounds heard over loudspeakers are essentially
illusory. They all have perceived spatial location and
behaviour in relation to a listener; some are particularly
clear whereas others, at the opposite extreme have "nowhere
in particular" as location and "stasis"
or "drift" as behaviour. The listener is aware
of his/her position in space relative to a sound or
environment. Our response, however, goes beyond simple
recognition of apparent location and behaviour of a
sounding object and our location in relation to it.
Other psychological, sociological and aesthetic responses
are triggered. Wishart identifies the principal, or
most obvious spatial opposition as
front and behind... Sounds coming
from behind....tend to be more stressful, mysterious
or frightening... This separation of in front
and behind also has a social dimension
for most higher animals." [Wishart, 1985]
sounds at extreme left and right positions suggest dialogue
or opposition. And the distinction between "present"
and "distant" suggest levels of engagement
from participation to observation as does the distinction
between a sense of envelopment and a perceived single
of movement and regularity and shape of motion, too,
are important factors in the characterisation of space.
Fast motion expresses energy; slow movement may imply
passivity; regular motion suggests something mechanical;
angular, irregular motion may convey hesitancy or uncertainty.
sum up, there are a number of ways of expressing structural
distance or separation: perceived physical
distance, distance of recognition, transformation between
different objects/sounds, distance between observation
and participation, and psychological or social distance.
We also know that characteristics of spatial behaviour
play a crucial part in our interpretation of sound morphologies,
contribute to our recognition of materials and give
significance to unfamiliar materials.
musical structure, then, relies so heavily on spatial
factors, it becomes obvious that careful public presentation
is essential to preserve musical meaning in an acousmatic
work. For even if the composer considers space and spatialisation
very carefully in the compositional process, experience
shows that as soon as a piece is played in another room,
many aspects of the sound are subject to the acoustic
qualities of that room and the many varied positions
of the members of the audience. Spatial details become
unclear, the effect of dynamic range is reduced by reverberation,
background noise and other factors and subtle timbral
relationships can be severely affected.
problems have been tackled by composers in many ways,
but one can usefully divide composers into two groups:
those who wish to standardise the listening experience
or neutralise the listening environment, and those who
seek to make use of the characteristics of every new
space and extend the creative act into performance.
those in the first group, the objective would seem to
be a much greater degree of control over spatial location
and behaviour. To achieve this usually involves multi-track
formats in order to translate particular 3-D spatial
movement into the concert hall, ambisonic encoding/decoding
which can compensate for the many problems encountered
with making even simple four channel presentation work
with any degree of success, or automated spatialisation.
However, these technically complex solutions make a
piece much less portable; they may preclude some venues;
control of spatial location does not necessarily solve
the problems of making real in a performance space the
spatiomorphology of sound; and the very specificity
might actually emphasise problems of, for example, audience
orientation. Nor do some of these solutions allow for
the different dynamic shaping needed for different spaces
and contexts. The extra control afforded by more complex
systems may, paradoxically, create a situation of diminished
even if we could overcome these difficulties, let us
not forget that the translation of a piece of music
into a listening space is not only a set of technical
problems, but also an opportunity to interpret the virtual
space in the actual acoustic by a performer and for
a particular public.
those in the second group, material (in whatever format)
should imply shapes and spatialisation which can be
optimised in performance for a wide range of venues.
Simple stereo encoding is already rich and multi-track
formats offer yet more possibilities. Of course, an
invitation to a performer to alter carefully composed
details has its dangers, but even for pieces from the
first group, a degree of sensitive diffusion is often
the grammatical details and the psychological messages
of spatial apprehension are unstable because they
depend not only on space as composed, but on the relationship
between the composed space and the space(s) in which
listening takes place....
the personal listening space and the diffused listening
space are open to widespread abuse which undermines
spatial perception. [Smalley, unpublished]
how should we respond to this in performance? In simple,
practical terms, what should we do?
let us define the parameters we wish to translate in
venue: loudness (i.e. perceived volume); spatial dimensions
(width, depth, height); spatial location; motion/spatial
behaviour; distance & presence (related to a perceived
notion of observation versus engagement); reverberation
(of the performance space) and even timbre (where the
performance space has problematic acoustic anomalies).
the absence of a complex technical solution, assuming
the most common case (a work in stereo with a clear
stereo image to be conveyed and a fixed orientation),
a simple solution offers a number of possibilities for
a wide repertoire. Multi-speaker diffusion can adapt
to both the limitations and creative potential of a
range of possible venues: it doesnt require the
availability of particular loudspeaker positions or
audience seating arrangement; it doesnt require
a particular number of matching loudspeakers; it offers
a number of solutions to each challenge which allow
for the development of different performance styles.
It also allows anyone with even a modest mixing desk
and only a few loudspeakers to begin to explore the
"relationship between the composed space and the
space(s) in which listening takes place....".
follows is not intended to be an exhaustive discussion
of performance practice. Neither, for reasons which
should be clear from the
is it intended to be technical. Rather, I would like
to make some general suggestions and observations based
on experience of concerts in many spaces over a variety
of performance loudspeaker arrays, small and large.
Description is no replacement for experience so this
should be seen only as one possible starting point for
a practical exploration of performance. I trust that
other articles in this issue of the Journal will expand
on these ideas, offer alternatives and cover in more
depth areas which here are only mentioned.
us start with two loudspeakers in an imaginary concert
hall (though this assumption is already contentious):
where should they be placed? If they are put at the
extreme left and right of a typical stage in front of
an audience, there will usually be a significant "hole
in the middle" of the stereo image for much of
the audience. If we move the speakers in from the sides
to compensate for this, some listeners will be situated
outside the stereo image. Whilst the listener might
be able to perceive the movement in the stereo stage
from this vantage point, the level of engagement compared
to a listener within the stereo stage will be completely
different. And as we have already noted, engagement
can be an important structuring parameter, in contrast
to most instrumental music where we are usually mere
observers of action on a stage.
with our single pair of loudspeakers, distance from
the front of stage to the front row of audience may
be many times shorter than the distance to the back
row, again resulting in a difference in sense of presence.
If we can lift the loudspeakers high enough we may be
able to minimise the relative distance between sound
source and front and back rows, but everything will
then appear to come from above head height which would
hardly be desirable. And is the front row of audience
below or above stage level, and is the auditorium itself
flat or sloping? All of these factors will significantly
alter subtle though critical details of space and perspective
for large parts of an audience, and therefore change
(or destroy) musical meaning!
can begin to solve these problems with multiple pairs
of loudspeakers, each replicating the stereo signal,
each independently controlled.
two pairs of loudspeakers, a useful array would be one
wide-of-stage pair, with another pair towards mid-stage.
In combination these two pairs could provide a single
image for most of the audience across the sound stage
with no "hole"; used independently one can
emphasise width or focus.
additional loudspeakers one can emphasise distance with
a pair up-stage as far as possible. Perhaps only as
a fourth pair would one use loudspeakers behind the
audience, since (unless specified by the composer) this
is not a dimension used in stereo, and as noted above,
has a particular social/psychological significance (not
to be used lightly!). Other speaker placements would
depend more on the particular space. If possible one
would use height, perhaps using overhead-front, -side
and -rear speakers, and, possibly something with a less
definable overhead location. Additionally one could
use other spatially vague placements in contrast to
the ones mentioned above, perhaps to give a sense of
envelopment or added presence.
performance complexity increases the more speakers one
uses, and different techniques are needed for different
locations and different musics, but it should quickly
become apparent that many of the aspects of spatial
location and behaviour which we noted above can be articulated
with carefully placed and mixed pairs of loudspeakers.
Sound becomes an almost palpable plastic object in the
concert environment and the sense of space implied so
strongly in the medium takes on a real three-dimensional
quality appropriate to the venue.
even with a single pair of loudspeakers the performers
role is critical. Careful preparation of each piece
is necessary to judge appropriate levels for a work,
and in a programme of several works, performance of
each work needs to take into account of all of the others.
Adequate rehearsal time in the venue with the loudspeaker
configuration set up is indispensable and in addition
to skill with the particular diffusion instrument,
the performer needs to have a clear understanding of
each piece s/he is to perform in order to realise a
fragile art of sound diffusion. In a medium which
relies on the observation and discrimination of qualitative
differences, where spectral criteria are so much the
product of sound quality, this final act becomes the
most crucial of all. [Smalley, 1986]
article first appeared in the Computer Music Journal,
19:4 Winter 1995 and was rewritten in 1997 for the Journal
of Electroacoustic Music.
D. (1986)Spectro-morphology and Structuring Processes
in: S. Emmerson (Ed), The Language of Electroacoustic
Music (London, Macmillan)
J. (1994) Novelty, Progress and Research Method in Computer
Music Composition,Proceedings of the 1994 ICMC (Aarhus,
T. (1985)On Sonic Art (York, Imagineering Press)
D. (unpublished) Spectromorphology: explaining sound
J. (1994)The Extended Environment,Proceedings of the
1994 ICMC (Aarhus, Denmark, DIEM)
MacDonald is a composer and performer of electroacoustic
music. Currently the Director of the Electroacoustic
Studios at the Royal Scottish Academy of Music &
Drama, he is a member of Invisible Arts and a Director
of Sonic Arts Network. He has worked extensively with
the electroacoustic ensemble BEAST and for Sonic Arts
Network, producing and diffusing concerts throughout
Europe, and leading workshops in schools colleges and
part of the article may be reproduced or transmitted
in any form or by any means, without prior permission
of the individual authors.