How did West Side Story adapt Romeo and Juliet for musical theatre?

West Side Story serves as a 20th-century American adaptation of William Shakespeare’s Romeo and Juliet, transposing the classic tale of star-crossed lovers into the setting of a working-class neighborhood in New York City.12

Rather than the feuding noble houses of Verona, the musical centers on the rivalry between two street gangs: the Jets and the Sharks. The narrative arc mirrors the original play, following the immediate attraction between Tony and Maria—who are affiliated with opposing sides—and the tragic escalation of violence that leads to the death of key characters.2

The adaptation is defined by its innovative approach to theatre music, where composer Leonard Bernstein and lyricist Stephen Sondheim utilized a sophisticated score to mirror the characters' internal states. Bernstein blended contemporary jazz-inspired sounds and Latin rhythms with traditional operatic techniques, such as using music to reflect the distinct hopes and combative emotions of multiple characters simultaneously, as seen in the song "Tonight".1