The Influence of Multiple Variables on Torsion in the Bowed E-String
Abstract
This research is an empirical exploration of the torsional vibration in the bowed violin E-string
that is the cause of the E-string whistle. Multiple measurements are taken directly from the
violin string with a laser vibrometer. Evidence is presented that shows bow velocity as an
essential part of a multi-variable explanation. Other variables include forced resonances in the
E-string coupled from notes bowed on the A-string that influence the start-up of torsional
vibration and natural frequencies of the transverse vibration in the A-string and E-string that are
coincident and/or non-coincident with the natural frequency of torsion. An explanation is given
concerning the bowing features of torsion that effectively block the normal Helmholtz resonance
in the open E-string and allow both forced and natural E-string frequencies that have coincident
harmonics with the torsion frequency to phase-lock with torsion and couple in super-position.