Harmonica is the secondary protagonist of Sergio Leone’s epic 1968 Spaghetti Western film, Once Upon a Time in the West. He is a mysterious stranger who arrives in a Western town named Flagstone, in pursuit of vengeance against a man named Frank, the film’s main antagonist.

In the film’s opening scene, Frank sends three men to pose as Cheyenne’s men – and kill a gunman playing a harmonica, who is later given the nickname, “Harmonica”.

The writer and composer is the maestro Ennio Morricone.