ï~~Granular Synthesis with Cmix and MAX
Mara Helmuth
Columbia University
Music Department
New York, NY 10027
Texas A & M University
Music Department
College Station, TX 77843
mara@woof.music.columbia.edu, mara@silvertone.princeton.edu
Abstract:
Several granular synthesis programs on the NeXT will be shown. StochGran is an Interface Builder
Objective C interface to several Cmix instruments. In this new version, sampling granular synthesis,
more graphical features, and in-phase correlation of grains have been added. The second part of the
demonstration features a granular sampling MAX patches running in real time on the IRCAM Signal
Processing Workstation. Excerpts from a composition by the author for eight instruments and ISPW,
Evolutions, which was created with both StochGran and Max, will be discussed.
1 Introduction
Construction of complex sound from grains, or
small units of sound is known as granular
synthesis. Probability equations are often used
to control the large amount of parameter data
for the grains. This technique was first
described by lannis Xenakis [19711 in his
discussion of stochastic music. Barry Truax
[1988] and Curtis Roads [1988] have both
explored these techniques. StochGran is a
NeXTstep interface to a Cmix implementation
of granular synthesis instruments. The current
version of StochGran incorporates new
graphical features for more spontaneous
control over sound creation, and the
granulation of sampled sound. Real time
granular synthesis is possible with the IRCAM
workstation. The MAX graphical programming
language has been _used to create
granular sampling patches for composition and
stochastic improvisation. The computer part of
Evolutions, a piece for eight live instruments
and computer is created by MAX patches both
playing Cmix-created sound files, and
performing granular sampling in real time on
sampled acoustic instrument sounds.
2 Cmix under NeXTstep
Implementation: StochGran
StochGran allowed the composer to control a
large number of grain parameters stochastically
and independently. In the original version the
parameters were typed in manually for each of
the thirty-six fields. A Cmix score or data file
was written out, the sgran stochastic granular
synthesis instrument was run with
these parameters, and a sound file was written
to the disk. The sound file could be played
ICMC Proceedings 1993
449
4D.1
0
