Which composer wrote the melody interpolated in the intro to Metallica's “Don't Tread on Me”?

Leonard Bernstein wrote the melody interpolated in the intro to Metallica's “Don't Tread on Me.”

The opening references “America,” a piece Bernstein composed for the musical West Side Story. Metallica incorporated that recognizable melody into the song's introduction, creating a brief classical-theatrical connection inside a heavy-metal album.

“America” originated in West Side Story, whose music was composed by Bernstein. The musical premiered on Broadway in 1957 and became one of the best-known works associated with his career. The melody's appearance on The Black Album is an interpolation rather than a cover of the entire song.

This detail is easy to miss because “Don't Tread on Me” was not one of the album's five commercial singles. It was issued to rock radio shortly after release, but it did not receive a commercial single release. The song's title also refers to the Gadsden flag motto, adding another historical reference to its musical quotation.