Composer Ennio Morricone spoofs his own earlier Sergio Leone-helmed "Man with No Name" film scores with an over-the-top soundtrack, including shrill choral voices and a warbling whistle interwoven with a tinny recurring passage from Richard Wagner's "Ride of the Valkyries". Also the soundtrack reuses part of "Frank"'s theme from Once Upon a Time in the West (1968) for the shootout sequence.
Jack came to the cemetery looking for his brother the Nevada Kid. The Kid's tombstone read he died in April 1898. Jack says it is June 3, 1899, so the Kid had been dead for over a year by the time Jack got to the cemetery.