Once Upon a Time in the West is a soundtrack composed by Ennio Morricone, from the 1968 western film of the same name directed by Sergio Leone, released in 1972. The film score sold about 10 million copies worldwide.

The soundtrack features leitmotifs that relate to each of the main characters of the movie (each with their own theme music), as well as to the spirit of the American West. The theme music for the Claudia Cardinale character has wordless vocals by Italian singer Edda Dell'Orso.

It was Leone's desire to have the music available and played during filming. Leone had Morricone composed the score before shooting started and would play the music in the background for the actors on set.

The work is based on a tune called The Nag written by the jazz guitarist/composer John Scofield, of whom I have long been a fan and with whom I worked closely when writing Blood on the Floor (Mark-Anthony Turnage)
'The grim frenzy, the waste and the futility of war are all embedded in Silent Cities' (The Times).