The Commodore 64 has long been a staple of the chiptune and circuit bending scenes, but it's not often that you see the old computer converted into a fully-fledged musical instrument. That's exactly what enthusiast Jeri Ellsworth has done, splicing a C64's body on to the neck of a bass guitar, allowing her to control the sound through the on-board Sound Interface Device (SID) chip.
As Ellsworth explains in the video below, the mutant device uses piezo pickups to capture the vibrations from the strings, amplifying and low-pass filtering them before sending them to the SID. The result is a retro sound familiar to anyone who's used a C64. The only catch is the power consumption — Ellsworth's creation uses a grand total of 18 AA batteries, and she admits that it only lasted eight hours on its first real outing at Maker Faire.