The intro to Metallica's “Don't Tread on Me” interpolates the melody of “America” from West Side Story.
“Don't Tread on Me” appears on Metallica's 1991 album, commonly called The Black Album. Its opening musical idea draws on “America,” a number composed by Leonard Bernstein for the stage musical West Side Story. An interpolation uses recognizable musical material within a new work rather than presenting the entire earlier song as a cover.
This connection is easy to miss because the track quickly moves into Metallica's own heavy arrangement and lyrics. The song's title also references the Gadsden flag and the phrase “Don't Tread on Me,” which can lead listeners to focus on its historical imagery rather than its musical opening.
“America” should not be confused with “Tonight,” “Maria,” or “Somewhere,” other well-known West Side Story songs. The album notes specifically identify the melody used in the intro as “America.”