Gyrotyre: a dynamic hand-held computer-music controller based on a spinning wheel

This paper presents a novel controller built to exploit the physical behaviour of a simple dynamical system, namely a spinning wheel. The phenomenon of gyroscopic precession causes the instrument to slowly oscillate when it is spun quickly, providing the performer with proprioceptive feedback. Also, due to the mass of the wheel and tire and the resulting rotational inertia, it maintains a relatively constant angular velocity once it is set in motion. Various sensors were used to measure continuous and discrete quantities such as the the angular frequency of the wheel, its spatial orientation, and the performer's finger pressure. In addition, optical and hall-effect sensors detect the passing of a spoke-mounted photodiode and two magnets. A base software layer was developed in Max/MSP and various patches were written with the goal of mapping the dynamic behavior of the wheel to varied musical processes.