contributed articles
DoI: 10.1145/1965724.1965742
Non-specialists may be disappointed that composition includes seemingly arbitrary, uninspired formal
methods and calculation.c What we
shall see here is that calculation has
been part of the Western composition
tradition for at least 1,000 years, This
article outlines the history of algorithmic composition from the pre- and
post-digital computer age, concentrating, but not exclusively, on how it developed out of the avant-garde Western
classical tradition in the second half of
the 20th century. This survey is more
illustrative than all-inclusive, presenting examples of particular techniques
and some of the music that has been
produced with them.
A Brief history
Models of musical process are arguably natural to human musical activity. Listening involves both the enjoyment of the sensual sonic experience
and the setting up of expectations and
possibilities of what is to come: musicologist Erik Christensen described
it as follows: “Retention in short-term
BY MIChAEL EDWARDS
Algorithmic
Composition:
Computational
Thinking
The composer still composes but also gets
to take a programming-enabled journey of
musical discovery.
in Music
in the West, the layman’s vision of the creative artist is
largely bound in romantic notions of inspiration sacred
or secular in origin. Images are plentiful; for example, a
man standing tall on a cliff top, the wind blowing through
his long hair, waiting for that particular iconoclastic idea
to arrive through the ether.a Tales, some even true, of
genii penning whole operas in a matter of days, further
blur the reality of the usually slowly wrought process of
composition. Mozart, with his celebrated speed of writing,
is a famous example who to some extent fits the cliché,
though perhaps not quite as well as legend would have it.b
a I’m thinking in particular of Caspar David Friedrich’s painting From the Summit in the Hamburg
Kunsthalle.
b Mozart’s compositional process is complex and often misunderstood, complicated by myth, especially regarding his now refuted ability to compose everything in his head15 and his own statements
(such as “I must finish now, because I’ve got to write at breakneck speed—everything’s composed—
but not written yet” in a letter to his father, Dec.
30, 1780). Mozart apparently distinguished between composing (at the keyboard, in sketch-es) and writing (preparing a full and final
score), hence the confusion about the length of
time taken to write certain pieces of music.
c For example, in the realm of pitch: transposition, inversion, retrogradation, intervallic
expansion, compression; and in the realm of
rhythm: augmentation, diminution, addition.
key insights
Music composition has always
been guided by the composer’s own
computational thinking, sometimes
even more than by traditional
understanding of inspiration.
Formalization of compositional
technique in software can free the mind
from musical and cultural clichés and
lead to startlingly original results.
Algorithmic composition systems
cover all aesthetics and styles,
with some open-ended variants
offering an alternative to the fixed,
never-changing compositions that for
most of us define the musical limits.
IllustratIon By stuDIo tonne