You won’t believe it’s not an actual guitar! Stringy is a tiny guitar synthesiser soldering kit from Boldport.
Stringy synthesizes guitar sounds using an efficient implementation of the Karplus–Strong string-plucking synthesis algorithm implemented on a tiny PIC microcontroller. It can play notes over five octaves (twelve notes per octave) in either acoustic or electric guitar style.
Note: requires through-hole soldering!
Stringy was Project #14 of the Boldport Club.