String instrument strings, or play them by rolling the bell of a brass instrument such as a trombone on the array of strings. However, these are relatively rarely used special techniques. Other keyed string instruments, small enough for a strolling musician to play, include the plucked autoharp, the bowed nyckelharpa, and the hurdy-gurdy, which is played by cranking a rosined wheel. Steel-stringed instruments (such as the guitar, bass, violin, etc.) can be played using a magnetic field. An E-Bow is a small hand-held battery-powered device that magnetically excites the strings of an electric string instrument to provide a sustained, singing tone reminiscent
Hurdy-gurdy sensitivity of the buzzing bridge can be altered by turning a peg called a "tirant" in the tailpiece of the instrument that is connected by a wire or thread to the "trompette". The "tirant" adjusts the lateral pressure on the "trompette" and thereby sets the sensitivity of the buzzing bridge to changes in wheel velocity. When hard to trigger, the strike or the bridge is said "sec" (dry), "chien sec" or "coup sec". When easy to trigger, the strike or the bridge is said "gras" (fat), "chien gras", or "coup gras". There are various stylistic techniques that are used as