Using electromechanical instruments being controlled by a computer, a new rock band (literally a rock band) recently played The Beatles’ “Here Comes the Sun.”
The contraption has five parts to it that when it works in unison, it plays the song. The parts include a pinger, which fires small rocks at aluminum keys using solenoids, a spinner, which launches magnetic rocks, hematite, at pieces of marble. The rocks are usually launched by spinning magnets using applied motion stepper motors.
Other parts of the contraption include a slapper, which slaps the rocks with fake leather, and a buzzer which vibrates the plunger of a solenoid against a piece of marble.
The machine is controlled by a computer running a MIDI player.