Information Technology Reference
In-Depth Information
Fig. 7.6
Types of interactive dialogue.
u
is the user or artist;
c
is the “canvas” or constructive
space;
s
is the computational system, which when adaptive changes its behaviour over time
An
interactive
system, conversely, tracks its users actions and responds to them
within the same “canvas”, creating the potential for further development upon the
system's actions. This canvas may be an acoustic space, the virtual page of a word
processor, or even a physical sheet of paper. It then becomes possible to respond
to the system's output, potentially reshaping
its
direction as well as our own. The
outcome contains elements of both the system and user and attribution to each be-
comes blurred. An example is the MetaScore system (Hedemann et al.
2008
)for
semi-automatic generation of film music via control of a generative music system's
parametric envelopes.
An
adaptive
system extends beyond the interactive by developing its behaviour
over a time period. These systems change the dynamics of their responses according
to the history of observations or behaviours. This introduces a behavioural plasticity
which allows its activity to remain relevant and novel to its user. Tools falling into
this class often make use of dynamical systems such as neural nets (Miranda and
Matthias
2005
, Bown and Lexer
2006
, Jones et al.
2009
), evolutionary algorithms
(Brown
2002
) and ecosystems (McCormack
2003
, Jones
2008
; see also Chap. 2 in
this volume).
7.3.5 Introspection
Early theorists of computer music—partly, no doubt, as a consequence of the tech-
nological limitations of the era—placed emphasis on the purification of the com-
positional process as a way of better understanding our own behaviours, either per-
sonal or cultural (Supper
2001
, Hiller
1968
, Ames
1987
). To model the processes
that tacitly underlie a existing musical system, we must first formalise them in an ef-
fectively computable form; i.e. transform them into a set of algorithms, with which
we can generate new pieces that fall into the same class. By creating a computer
