In the 1980s, an American musician and composer called Ellen Fullman built an enormous musical instrument suitably called the Long String Instrument.
It had 56 metal wires that acted like strings which stretched over 50 feet in length. Fullman used violin rosin on her fingers to increase the friction. She rubbed them along the strings causing them to vibrate and produce a deep and ethereal droning sound.
To learn more about the Long Stringed Instrument please visit https://www.ellenfullman.com