Feldmeier, M. "Large Group Musical Interaction using Disposable Wireless Motion Sensors"

Abstract

One of the difficulties in interactive music and entertainment is creating environments that reflect and react to the collective activity of groups with tens, hundreds, or even thousands of participants. Generating content on this scale involves many challenges. For example, how is the individual granted low latency control and a sense of causality, while still allowing for information retrieval from all participants so that the environment responds to the behavior of the entire group? These issues are particularly pertinent in the area of interactive dance.

To address these issues, a low-cost, wireless motion sensor has been developed. The sensor is inexpensive enough to be considered disposable, allowing it to be given away to participants at large dance events, enabling the dancers to participate concurrently in a real-time, interactive musical performance. The sensors are either worn or held by participants and transmit a short RF pulse when accelerated past a certain threshold. The RF pulses are received by a base station and analyzed to detect rhythmic features and estimate the general activity level of the group. These data are then used to generate music that can either lead or follow the participants' actions, thereby tightening the feedback loop between music and dancer.

Multiple tests of the system have been conducted, with groups ranging from fifteen to 200 participants. Results of these tests show the viability of the sensors as a large group interaction tool. Participants found the interface intuitive to use, effectively controlling such aspects of the music as style, tempo, voicing, and filter parameters. These tests also demonstrate the system's ability to detect both the activity level and dominant tempo of the participants' motions, and give considerable insight into methods of mapping these data to musical parameters that give participants direct feedback as to their current state. Furthermore, it is shown that participants, if given this direct feedback, will synchronize their actions and increase in activity level, creating a mutually coherent and pleasing outcome.