Leonard Bernstein's composition “America” is interpolated in Metallica's song “Don't Tread on Me.”
“America” was written by Bernstein for the musical West Side Story. Metallica's album track uses the melody in its introduction, creating a brief connection between a classic Broadway work and a heavy-metal recording.
The wording matters: “America” is the composition, while West Side Story is the musical in which it appears. “Maria” and “Tonight” are also famous West Side Story songs, but neither is the melody used in the introduction.
“Don't Tread on Me” appears as the sixth track on Metallica. The song's title and imagery also connect with the Gadsden flag, whose motto is “Don't Tread on Me,” the same phrase used for the track title.