Synchronization in human-robot Musicianship

Shimon is a interactive robotic marimba player, developed as part of our ongoing research in Robotic Musicianship (RM). One of the potential benefits of RM is that it provides human players with embodied information that relates spatial movement to tone generation. This can aid in anticipation and coordination of synchronous playing. As part of a human-robot Jazz improvisation system, we present an anticipatory system enabling beat-matched real-time synchronization. Our system enables flexible, yet coordinated call-and-response, a standard type of musical interaction. It was used in a live public human-robot joint Jazz performance. We also describe a preliminary study evaluating the effect of embodiment on this call-and-response musical synchronization task. We conducted a 3×2 within-subject study manipulating the level of embodiment (visual co-presence, physical presence but visual occlusion, and synthesized sound), and the accuracy of the robot´s response. Our findings indicate that synchronization is aided by visual contact when uncertainty is high, but that pianists can resort to internal rhythmic coordination in more predictable settings. We find that visual coordination is more effective for synchronization for slow sequences compared to faster sequences; and that occluded physical presence may be less effective than audio-only note generation.