Spoiler Alert The basic fact is that Harmonica(Charles Bronson) has a long standing enmity with the movie's main villain Frank( Henry Fonda in an unlikely role). Now what exactly is the reason for this enmity is revealed at the end in a flashback, which has to be seen in the movie. read more
Harmonica sees the opportunity to take revenge on Frank, by helping the Widow, along with the bandit Cheyenne. In a sense, Frank is the common enemy for all the 3, he had framed Cheyenne for the murders of McBain and his 3 kids. read more
In ONCE UPON A TIME IN THE WEST, three men in long duster coats wait at a train station. The train arrives, and the man they are sent to kill, simply known as Harmonica (Charles Bronson), instead dispatches them. read more