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IR for Contemporary Music: What the Musicologist Needs
Abstract of an invited talk given at the International Symposium on Music Information Retrieval (MUSIC IR 2000), Plymouth, MA., October 23-25, 2000.
© Ircam 2000
Active listening is the
core of musical activity
Listening does not only concern receiving
musical information. On the contrary, it is active and based on a set of
interactions between listeners and musical documentsincluding automatic music
information research and extractionso as to discover intentions. This
recognition process is based on the observation of regularities and rules, in
order to build forms from all indications, information and redundancies. The
listener interprets all the signs that are meaningful for him as intentions,
attributed to the composer.
Features of computer
Let us specify further the active listening situation for the musicologist, taking
for example the
consultation of a document in
such a digital library as
The musicologist is facing a computer
screen, while handling scores and books. This
terminal allows him, among many other possibilities,
to listen to music, to access musical data bases and hypermedia
analyses. The musicologist is handling several devices
on several media at the same time.
First of all, the listener needs a framework
that takes him/her into account. The purpose is to set the conditions of
possibility of listening by restricting the heuristics of forms. It is
therefore necessary to set a listening framework for the musicologist, to
assist him in discovering the intentions of music. The main feature of this
listening environment is thus
its capacity to enable its user to vary the music representation. In the
same way that working on a musical piece leads us
either to read it silently or to sol-fa, or to hum it, or to play it, the
musicologists environment must enable rapid changes of the
representation of abstract objects.
This is very important: a critical part
of the analysis work consists in associating varied representations and
purpose is the emergence of meaning from numerous and dissimilar elements that
views imagined by the musicologist manage to reconcile. Musical databases help
weave these links. In such an environment as the IRCAM Digital Library, we can
various representations of music: hypermedia analyses offer sonograms as well
as scores or formal schemes.
associate various contexts: the musicologist can easily know which works are
contemporary with the Marteau sans Maître
by Boulez using roughly the same instruments, or explore the musical production
of the year 1954.
We use here the expression contemporary music
for Western art-tradition music written since 1945. However this
definition is controversial, and a lot of ambiguity
remains in identifying works that belong to it. But it avoids, at least
provisionally, the stumbling
block of the stylistic definition.
To characterize it, we use the musicologists
point of view, with his/her tools, either computerized or not. The musicologist
is at the same time a listener and a composer, since analyzing a piece a music
leads to rewriting it.
The first difficulty the musicologist faces in
contemporary music is the confusion in listening. Looking for reference marks,
the listener is in a way considerably free, but he is deprived from the
listening guiding towards intentions we evoked before. Let us examine the
consequences of this confusion in terms of automatic research of musical
- The first point is the decline of melody, which used to be the fundamental basis in
musical composition. Structural objects used by composers are no longer the
ones which are part of the horizontal entities perceived (cells, figures). This
raises two kinds of problems:
- the first one concerns the computation of the musical surface, that
is to say the automatic determination of outstanding elements of a
polyphonic music, by combination of structural and sound criteria (instrumental
features, timbres, masking effects, etc.).
- the second one deals with the
research of melodic elements which play a structural role, such as mottos.
- The second point concerns the difficulty of extracting and interpreting harmonic data from contemporary music
works. There is no longer a reference system. This problems has arisen since Debussy: in his music, he
often forgets to resolve certain dissonances, which progressively become part
of his harmonic vocabulary.
- The relationship to form: in his effort to
recognize intentions, the listener eliminates time from movement, to get the
trajectory and the form. The latter derives from a spatial conception; in its
expression, it is often mistaken for its structure. The classical sonata is
often described according to a rhetorical and intemporal scheme
exposition/development/reexposition. Contemporary music proposes two major
evolutions in that field:
- form can be attached to other
representations than symbolic structures: spectral music thus often uses paths
through sound spectra
called interpolations that contribute to the form. To our knowledge,
there is no automatic tool able to interpret
this kind of data at the scale of a form.
- many contemporary composers do not want form to reveal
itself simply, as a reducing logical scheme, for instance the ABA scheme for
the aria da capo. But the
possibilities of using operating filters as algorithms in automatic search,
to be able to handle complex forms, are still limited.
- Last but not least, we have only evoked music using traditional instruments.
Electroacoustic and mixed (computer plus instruments) raise the representation
problem: which information structures is it possible to extract from
the audio file of such a piece as Artikulation
by Ligeti? How can we handle inharmonic sounds?
A synthesis of the musicologists needs
Our first remark is that the choice of the
contemporary catalogue does not modify the nature of the musicologists work
nor his/her purposes. However it seems that this task is more difficult and
less systematic for contemporary music. The musicologist must set together by
himself formal filters enabling him to account for the composers intention,
starting from directories of simple form bearing elements and classical
We state that the musicologists workstation
must have the following features:
- It proposes varied representations of music and circulation possibilities among
them, breaking away from physical separations between their producers. It must
thus propose to the musicologist the computerized tools and files uses by the
composer as he/she was elaborating the piece, if possible. The representations
that the musicologist will link together during his/her analysis work are:
- the graphical representations (paper
score, sonogram, formal scheme, etc.),
- the sound representations (audio),
- the symbolic representations (MIDI,
computerized description of the score, etc.),
- if necessary, the
tool-representations that concern the working steps of the composer using the
- It allows for the active listening of music in a broad meaning, by consulting
different musical documents, each of them being associated to one or several
representations we have described.
- It must allow for the reconciliation of reading and writing on the same
media. In traditional music analysis, these two phases are split, since the
musicologist reads a score and moreover writes a document in a literary form,
without any possibility of dynamic link between the two. On a terminal, it is
important that the musicologist may have possibilities of writing and
annotating on musical objects represented on the screen. In the case of mixed
musics, associating computer and instruments, the musicologist has to be able
to use the sketch computerized environment run by the composer.
- To face the difficulty of analyzing contemporary music, the system proposes to the
listener/musicologist to build his own adequate structures to
look for forms using specific languagues to encode the patterns, either global
or local. The form bearing elements may be:
These form bearing
elements can be hierarchically set together as trees, to build a form search
- either musical , to be looked
for in symbolic representations (as different kinds of intervals of notions
such as the longest sequence of joint intervals, or the longest sequence of
disjoint intervals, etc.),
- or related to sound, to be looked
for in signal representations (search for harmonic zones, peaks, etc.)
- or operating processes (fractals,
mathematic transformations, etc.).
- It includes learning mechanisms, such as:
- saving of works achieved by each musicologist,
- saving of approaches lead for each of the analyzed pieces,
- enriching the directories including form bearing elements and elementary structures.
Examples of implementation in IRCAM projects
Two European projects including IRCAM
partnership answer part of these expectations:
- the CUIDADO (Content-based Unified Interfaces and Descriptors for Audio/music
Databases available Online) project deals with description and research of
audio files, in conjunction with the proposed MPEG7 standard. Form bearing
elements are here low level data extracted from signal to be statically
correlated to high level descriptors such as genre information. Among proposed
functionalities, let us notice: the fast search of sound files, of similarities
between audio contents, the creation of user profiles, the editing and
classification of sounds.
WEDELMUSIC (Web Delivery of Music Scores) project proposes a system of online
distribution of scores or fragments of scores. The musicologist has
possibilities of research of musical structures, of comparison and annotation.
There is still much work remaining to propose a
coherent set of software and devices dedicated to contemporary music.
- [Berio 1981]
- Berio, Luciano, 1983. Intervista sulla musica, a cura di
Rossana Dalmonte, Roma, Bari, Laterza.
- [Lerdahl 1988]
- Lerdahl, Fred, 1988. « Structure de prolongation
dans latonalité », in La musique et
les sciences cognitives, Bruxelles, Mardaga, pp. 103-135.
- [Rousseaux 1990]
- Rousseaux, Francis, 1990. Une contribution de
lintelligence artificielle et de lapprentissage symbolique automatique à
lélaboration dun modèle denseignement de lécoute musicale, Thèse de
doctorat, Université Paris VI.
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