A Study of Certain Secondary Phenomena in the Motion of the Bowed Violin String

Abstract

As long as there have been violins, people have wondered how a few rosin-coated strands of horsehair on a violin bow could produce a steady tone when drawn across a string. Hermann von Helmholtz,, although not the first to ask this question was the first to devise a quantitative answer. His model, based on actual observations, remains a classic to this day, and succeeds in explaining the behavior of the bowed string to a surprising degree. J. c. Schelleng, a more recent investigator, has called attention to some significant departures from the Helmholtz model. In order to account for these departures, Schelleng suggested: 1) that wave pulses could be trapped between the bow and the supports, and 2) that the string might roll beneath the bow, in addition to its transverse motion. In this paper, the Helmholtz model will be briefly presented, along with Schelleng's additions to that model. Some alternative hypotheses will be developed, and experimental evidence will be produced which tends to indicate that: 1) standing waves develop between the bow and the bridge of the violin, and 2) violin strings really do roll beneath the bow, and that such rolling takes the form of standing torisonal waves on the string.