  Musical counterpoint, a musical technique in which two or more independent
melodies are played simultaneously with the goal of creating harmony, has been
around since the baroque era. However, to our knowledge computational
generation of aesthetically pleasing linear counterpoint based on subjective
fitness assessment has not been explored by the evolutionary computation
community (although generation using objective fitness has been attempted in
quite a few cases). The independence of contrapuntal melodies and the
subjective nature of musical aesthetics provide an excellent platform for the
application of genetic algorithms. In this paper, a genetic algorithm approach
to generating contrapuntal melodies is explained, with a description of the
various musical heuristics used and of how variable-length chromosome strings
are used to avoid generating "jerky" rhythms and melodic phrases, as well as
how subjectivity is incorporated into the algorithm's fitness measures. Next,
results from empirical testing of the algorithm are presented, with a focus on
how a user's musical sophistication influences their experience. Lastly,
further musical and compositional applications of the algorithm are discussed
along with planned future work on the algorithm.
