Abstract: A percussion instrument incorporates a case with an inner surface having a substantially circular profile. Multiple high precision spherical balls are contained with the case for acceleration on the inner surface in uniform circular motion along the profile to produce a persistent sustained sound. In one exemplary embodiment the case is cylindrical and incorporates two end plates. In a second embodiment the percussion instrument case is torroidal. In a third embodiment the percussion instrument case is spherical. Use of varying materials in the case or differing surface textures on the inner surface allows timbre of the instrument to be modified. Motion of the instrument lateral or perpendicular to the circular profile allows the creation of pulsed percussion sounds.

Abstract: A percussion instrument incorporates a case with an inner surface having a substantially circular profile. Multiple high precision spherical balls are contained with the case for acceleration on the inner surface in uniform circular motion along the profile to produce a persistent sustained sound. In one exemplary embodiment the case is cylindrical and incorporates two end plates. In a second embodiment the percussion instrument case is torroidal. In a third embodiment the percussion instrument case is spherical. Use of varying materials in the case or differing surface textures on the inner surface allows timbre of the instrument to be modified. Motion of the instrument lateral or perpendicular to the circular profile allows the creation of pulsed percussion sounds.