ï~~Position Paper for Music Representation Panel
Lounette M. Dyer
CCRMA
Stanford University
Stanford, CA 94305
loon@parcplace.com
Introduction
A multitude of computer music software applications have been developed over the last two
decades encompassing a wide variety of application areas, including music synthesis, music
editing and printing, and computer aided composition. More recently, realtime control of
music synthesis has become an important application area. Developers of computer music
applications typically use music representations that are tailored to the specific application.
In the case of synthesis applications, the representation was usually very tightly coupled
to the particular synthesis algorithms and synthesis hardware. As a result it was difficult
or in some cases impossible to share scores among applications or to perform scores on
computer systems that were different from the one that originated the score. Attempts to
write conversion programs between representations were not very successful as information
was often lost between these application-specific representations. (For example, many
applicatons used a keynumber to represent pitch which caused enharmonic pitches to be
aliased.)
CAD Workstation for Musicians
The availability of powerful and inexpensive personal computers (with a graphics monitor
and a mouse) and realtime synthesizers have caused computer music systems to rapidly
evolve toward single user systems that support heterogenous synthesis hardware (MIDI
synthesizers, DSP boards, etc.) and realtime control hardware. Thus, the time seems ripe
for the development of the musician's equivalent of a CAD workstation (Music-CAD or
M-CAD)-a workstation for the creation and manipulation of music and sound. Such a
workstation would provide an integrated set of tools for all aspects of music and sound
creation, from inception, through experimentation, to printing and performance. An MCAD system would benefit greatly from a standard computer music representation by
providing a foundation for the integration of applications.
Computer Music Representation
A music notation is a system of written symbols, a language if you will, by which musical
ideas are represented and preserved for study and performance. Thus the notation acts as a
set of instructions to performers who will create the sound of the music. A computer music
representation (CMR) could be thought of as a digital encoding of a music notation, by
which musical ideas are represented and preserved for performance and study by machines.
A CMR must provide at least three components: a standard ASCII score file format, runtime data structures, and a set of manipulation functions. M-CAD systems are somewhat
unique in that new computer music hardware technology (both synthesis and realtime control hardware) is being introduced at a very rapid pace. Therefore, the envisioned M-CAD
system would tie together the three above components with a design methodology that
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