“Don't Tread on Me” from Metallica's The Black Album interpolates Leonard Bernstein's melody “America.”
The melody comes from West Side Story, the musical associated with Bernstein's music and Stephen Sondheim's lyrics. Metallica placed the recognizable passage in the introduction of “Don't Tread on Me,” creating an unusual link between a 1950s Broadway work and a 1991 heavy-metal album.
An interpolation uses a recognizable musical idea within a new composition or arrangement; it is not the same as simply adding a separate cover recording. The Black Album's liner and track notes identify the connection, which is why “America” is the precise answer rather than the broader title West Side Story.
“Don't Tread on Me” was issued to rock radio after the album's release but was not released as a commercial single. The album's official singles were Enter Sandman, The Unforgiven, Nothing Else Matters, Wherever I May Roam, and Sad but True.
The song is track six on the standard album and follows “The Unforgiven” in the sequence.