Which Instrument Covers Crinkling Cough Drops?

“Working with programmers, a computer vision expert and an adventurous saxophone quartet, [a Georgia composer] is creating a work in which a restless audience is very literally part of the music. Listeners and musicians are encouraged to wander around the performance space during the concert, while digital cameras track their motion. Those movements are fed into a software simulation, and Freeman’s algorithms, using parameters such as distance from performers, speed and ‘sheepiness,’ use the data to dynamically create a score on Pocket PCs attached to the musicians’ instruments.”