Abstract: A method and apparatus is provided for the adjustment of resonance on a freely vibrating filament by the use of piezoelectric pushers which are solid state devices whose lengths change as a result of applied voltage. The pushers are configured in such a manner that changes in the pushers' lengths are translated into changes in resonance. The pushers are controlled by feedback circuit wherein frequency of vibration is compared to an electronically generated reference. The resulting error signals are input to DC amplifiers which drive the piezoelectric pushers so as to eliminate the error.