Published online by Cambridge University Press: 18 January 2008
One may produce the qth harmonic of a string of length π by applying the 'correct touch' at the node $\pi/q$ during a simultaneous pluck or bow. This notion wasmade precise by a model of Bamberger, Rauch and Taylor. Their 'touch' isa damper of magnitude b concentrated at $\pi/q$ . The 'correct touch' is that b for which the modes, that do not vanishat $\pi/q$ , are maximally damped. We here examine the associated spectralproblem. We find the spectrum to be periodic and determined by a polynomialof degree $q-1$ . We establish lower and upper bounds on the spectral abscissaand show that the set of associated root vectors constitutes a Riesz basisand so identify 'correct touch' with the b that minimizes the spectral abscissa.