Which musical is referenced by the opening melody of Metallica's song “Don't Tread on Me”?

The opening melody of Metallica's song “Don't Tread on Me” references “America” from the musical West Side Story. The phrase appears as an eight-bar introduction before the song's main material.

“America” was composed by Leonard Bernstein for West Side Story, the musical created by Bernstein, Stephen Sondheim, Arthur Laurents, and Jerome Robbins. Its recognizable melody gives the Metallica track an unusual connection to a classic American stage production.

The song's title and lyrics also point toward American Revolutionary imagery. “Don't Tread on Me” is the motto of the Gadsden flag, whose snake appears on The Black Album's cover. The title therefore links the track musically and visually to American historical symbols.

Don't Tread on Me was included on the 1991 album but was not one of the record's five commercial singles. It was instead issued as a promotional single for rock radio shortly after the album's release.