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
Early Music (Lachrymæ Antiquæ) album in which "the distinctions between old and new are blurred, and the effect is comforting rather than disconcerting." As with many Kronos Quartet albums, the basic string quartet is augmented by various other, sometimes exotic instruments. The Swedish song "Längdans efter Byfåns Mats" features a bagpipe, and the traditional Swedish bridal march "Brudmarsch frå Östa" includes a nyckelharpa (a string instrument related to the hurdy-gurdy). Chinese virtuoso musician Wu Man plays two kinds of ruan (a plucked lute-like string instrument) on "Lachrymæ Antiquæ." Perhaps the most exotic instrumentation is found on "Uleg-Khem", a traditional Tuvan song, where the quartet