Metallica's “Don't Tread on Me” interpolates the melody of “America” from West Side Story.
The interpolation appears in the song's intro, connecting the album track to Leonard Bernstein's music for the stage musical. The reference is brief and instrumental, so it is easy to overlook beside the song's central hard-rock riff and patriotic imagery.
“America” is one of West Side Story's best-known musical numbers. Bernstein composed the music, while the musical's lyrics were written by Stephen Sondheim. Metallica did not record a full cover; it incorporated a recognizable melodic passage into an original song.
The track also has a release-history distinction. “Don't Tread on Me” was issued to rock radio soon after the album appeared, but it was not released as a commercial single. The album's five commercial singles were different songs.