The instrument in this video was built by a Ph.D. student (Alloy Electric) in computer music at UCSD who builds real and imaginary instruments and programs audio effects.
"This is an instrument I originally built to make the sound design for Rosencrantz and Guildenstern Are Dead. It is a computer-controlled feedback loop which engages the strings as a sort of resonant memory. Any sound made in its vicinity will hang sustained in the air as it is slowly transformed. Its sound is at once familiar and alien, a fitting backdrop for the surreal world inhabited by these characters."
You can hear more of this stringed instrument among others on the album Diverse Recourse by Joe Beats.
