Jet-Boot Jack (also called The Music Machine starring Jet-Boot Jack) is a platform game written by Jon Williams for the Atari 8-bit family and published by English Software in 1983. It was ported to the Acorn Electron, Amstrad CPC, BBC Micro, and Commodore 64. A C64-only sequel, Legend of the Knucker-Hole, was released in 1984.