Which musical supplied the melody interpolated in Metallica's “Don't Tread on Me”?

Metallica's “Don't Tread on Me” interpolates a melody from the musical West Side Story.

The melody appears in the song's introduction and comes from “America,” a number composed by Leonard Bernstein for West Side Story. Metallica's use of the passage is a brief musical reference rather than a cover of the complete song. The connection is easy to miss because it is embedded within a heavy metal arrangement.

“Don't Tread on Me” appears on The Black Album and takes its title from the historical “Don't Tread on Me” slogan associated with the Gadsden flag. The song's lyrics and imagery draw on American patriotic symbolism, which gives the borrowed musical phrase an additional contextual resonance.

The track was issued to rock radio after the album's release but was not released as a commercial single. That distinction separates it from the album's five commercial singles: “Enter Sandman,” “The Unforgiven,” “Nothing Else Matters,” “Wherever I May Roam,” and “Sad but True.”