The music was composed by Leonard Bernstein, and the lyrics were written by Stephen Sondheim.
West Side Story is a modernized adaptation of Shakespeare's Romeo and Juliet set in 20th-century New York; the scene in which "Tonight" appears is the adaptation of Romeo and Juliet's famous "balcony scene".
[2] In the original 1957 Broadway production of West Side Story, "Tonight" was performed by Larry Kert and Carol Lawrence in the roles of Tony and Maria.
In the 1961 film adaptation of the musical, the song was performed by Marni Nixon (dubbing Natalie Wood as Maria) and Jimmy Bryant (dubbing Richard Beymer as Tony).
In the 2021 film adaptation, it was performed by Rachel Zegler as Maria and Ansel Elgort as Tony, and was released as a digital download single of the film's soundtrack album on December 1, 2021.