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
Nyckelharpa Nyckelharpa A nyckelharpa (, "keyed fiddle", or literally "key harp", plural "nyckelharpor") is a traditional Swedish musical instrument. It is a string instrument or chordophone. Its keys are attached to tangents which, when a key is depressed, serve as frets to change the pitch of the string. The nyckelharpa is similar in appearance to a fiddle or the big Sorb geige or viol. Structurally, it is more closely related to the hurdy-gurdy, both employing key-actuated tangents to change the pitch. A depiction of two instruments, possibly but not confirmed nyckelharpor, can be found in a relief dating from "circa" 1350