of Microprocessors

18
Music Synthesis
Software
With few exceptions, the entire discussion up to this point has concentrated
on hardware-related items, both digital and analog. The key to a successful
computer music system, particularly one utilizing direct synthesis techniques,
however, is efficient and easy to use software. Actually in the final
analysis, software is the real frontier in computer music regardless of the
sound generation technique utilized. Little of the preceding hardware discussion
can be considered "new" and almost certainly none of it is revolutionary.
On the other hand, any given programmer with a suitable knowledge of
music and synthesis techniques can create a music-oriented programming
system significantly different from othets that have been done and may
possibly stage a software breakthrough. This is as it should be, since, after
all, the general-purpose computer was conceived as a finite hardware device
with infinite application possibilities through programming.
Computer music "systems," where a system is the combination of
musical I/O hardware with software "glue," can be separated into two easily
distinguishable groups. The first group covers systems designed for real-time
performance directly from manual input devices such as keyboards and
source-signal analysis. The second group covers "programmed" performance,
either real-time or not, in which the sounds are carefully specified prior to
the actual synthesis. While the former type of system has not been emphasized
in this text, it is of interest to a great many people. In terms of
software, however, such systems tend to be specialized for particular combinations
of input devices and synthesis techniques. The second type of system
tends to be much more general. Often, these develop along classic software
system lines with the concepts of tasks, events, macros, supervisors, and
languages being integral parts.
In this chapter, programming techniques for the programmed performance
type of system will be discussed. In addition, the anatomy of a
simplistic but expandable music software system will be described. It is
immaterial whether the synthesis is performed in real time or not, since the
"score" is definitely prepared outside of real time. In most cases, nonreal-time
delayed playback direct synthesis will be assumed because it is more general
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