The digital bow

Abstract

The “digital bow” is a device that senses the instantaneous velocity of a chosen point on a string and, by looking up an equivalent frictional characteristic stored in a computer table, exerts an electrodynamic force on the string corresponding to what a physical bow would do under the same circumstances. The process is repeated at a high sampling rate in real time. Under such conditions, we observe the string breaking into spontaneous Helmholtz motion. The arrangement is of great interest to the physicist because it provides exact control of the frictional characteristic of the “bow,” allowing one to investigate details of the bowing process to a degree hitherto unattainable. It may also have considerable musical potential, since the behavior of this “bow” is not limited by the properties of Siberian horse hair or of the secretions of dripping evergreens. Video and audio tapes will be presented. [Work supported in part by NSF.]