GenJam: A Genetic Algorithm for Generating Jazz Solos

Abstract

This paper describes GenJam, a genetic algorithm-based model of a novice jazz musician learning to improvise. GenJam maintains hierarchically related populations of melodic ideas that are mapped to specific notes through scales suggested by the chord progression being played. As GenJam plays its solos over the accompaniment of a standard rhythm section, a human mentor gives real-time feedback, which is used to derive fitness values for the individual measures and phrases. GenJam then applies various genetic operators to the populations to breed improved generations of ideas. 1 Introduction As with most problem-solving activities, musical tasks like composition, arranging and improvising involve a great deal of search. Composers search for the right chords to fit a melody or the right melody to fit a chord progression