“Don’t Tread on Me” is the Metallica song from The Black Album whose intro interpolates Leonard Bernstein’s “America.”
Bernstein wrote “America” for the musical West Side Story. Metallica’s track uses the recognizable melody in its opening, creating a brief contrast before the song moves into the band’s heavy-metal arrangement. The interpolation is credited in the album’s notes and is one of the record’s more distinctive musical details.
This is not a cover of the complete Bernstein song. An interpolation incorporates or adapts part of an existing musical passage within a new composition, while a cover performs an existing song as a song in its own right.
“Don’t Tread on Me” was also sent to rock radio after the album’s release, but it was not issued as a commercial single. That distinction separates it from the album’s five official commercial singles.