Improvised duet interaction: learning improvisation techniques for automatic accompaniment

The interaction between music improvisers is studied in the context of piano duets, where one improviser performs a melody expressively with embellishment, and the other plays an accompaniment with great freedom. We created an automated accompaniment player that learns to play from example performances. Accompaniments are constructed by selecting and concatenating one-measure score units from actual performances. An important innovation is the ability to learn how the improvised accompaniment should respond to the musical expression in the melody performance, using timing and embellishment complexity as features, resulting in a truly interactive performance within a conventional musical framework. We conducted both objective and subjective evaluations, showing that the learned improviser performs more interactive, musical, and human-like accompaniment compared with the less responsive, rule-based baseline algorithm.