Musical by Leonard Bernstein, Stephen Sondheim and Arthur Laurents; premiered in 1957
West Side Story is a musical conceived by Jerome Robbins with music by Leonard Bernstein, lyrics by Stephen Sondheim, and a book by Arthur Laurents. Inspired by William Shakespeare's play Romeo and Juliet, the story is set in the mid-1950s in the Upper West Side of Manhattan in New York City, then a multiracial, blue-collar neighborhood. The musical explores the rivalry between the Jets and the Sharks, two teenage street gangs of different ethnic backgrounds.
https://en.wikipedia.org/wiki/West_Side_Story