The Computational Creativity Complex - Computational Creativity Research: Towards Creative Machines - page 72

Fig. 4.4 A portion of a lead sheet created by CARL. The full melodic line was created using a
genetic algorithm on an initial population of concatenated motifs discovered from the input file
Bioplazm2.jpg . Harmonization was accomplished using the Viterbi algorithm on an HMM which
was trained on a lead sheet database
taking the dot product of the appropriate row in the melody emission matrix with the
pitch vector that represents the measure, and this constitutes the emission matrix of
a hidden Markov model. The Viterbi algorithm is used to calculate the most likely
chord sequence that accompanies the given melody.
Figure 4.4 shows part of a lead sheet created by CARL when the inspirational
source was an abstract image file called Bioplazm2.jpg .
4.2.3 PIERRE
PIERRE is a system for culinary creation, which, given access to existing recipes,
learns to produce new crockpot recipes. PIERRE is composed primarily of two mod-
ules, for handling evaluation and generation, respectively. Each of these components
takes input from an inspiring set and each is involved in producing recipes to send
to the presentation module, as shown in Fig. 4.5 . In addition, the system interacts
with the web, both acquiring knowledge from online databases and (potentially)
publishing created recipes.
Recipe generation is a complicated task that requires not only precise amounts
of ingredients but also explicit directions for preparing, combining, and cooking the
ingredients. To focus on the foundational task of the type and amount of ingredients,