Computational Creativity and Music - Computational Creativity Research: Towards Creative Machines - page 306

nature—I center on triads and voice leading along with description of a computer
program and its output. Finally, I present a sample of creativity in counterpoint, once
again demonstrating both human and computer-generated music.
15.3.1 Melody
Most composers sketch as an integral part of their creative processes, often using
associations on their way to developing variations and new ideas.
Figure 15.2 provides an example of such a process.
Beethoven is noteworthy for keeping notebooks of sketches of melodic ideas that
have, since his death, been published and referenced for all to see. In Fig. 15.2 ,we
see roughly the same theme in two different guises composed two years apart. The
projected symphony in 2(a) was never completed, but by cannibalizing it, Beethoven
reveals he thought well enough of the theme to include it in a slightly different guise
in a later published work. Is (b) then more creative than (a) according to Beethoven?
Note that while transposed to G-major and metrically offset, Fig. 15.2 b's opening
measures are identical to (a) for the first five notes. The music then varies in quite
interesting ways both in rhythm and pitch and ends with a hint of G-minor with
the Bb nine notes from the end (2b). The range, when appropriately transposed,
remains the same with the final note the same as well. Within those frameworks,
however, Beethoven has not just embellished his original idea, but also neatly crafted
a surprisingly creative variation.
Figure 15.3 provides an even more interesting example of sketching with (a) being
the first and (b) the eleventh sketch with, obviously, nine continuously improving (at
least in Beethoven's opinion) ones in between.
These examples showamuchmore drastic range of changes than those in Fig. 15.2 ,
with the more or less final version—excepting the second and fourth measures—
varying significantly from the initial one. Unlike Fig. 15.2 , which simply leaps from
one version to the other, this example slowly—through the missing sketches—
Fig. 15.2 a Opening bars of finale theme by Beethoven of projected symphony from 1795; b Rondo
from Sonata Op. 49, No. 1 from 1797 by Beethoven