The stage musical West Side Story was created by a team:

  • Concept and direction: Jerome Robbins
  • Music (score): Leonard Bernstein
  • Lyrics: Stephen Sondheim
  • Book (script): Arthur Laurents

So if you’re answering “who wrote West Side Story ,” the most accurate reply is that Leonard Bernstein, Stephen Sondheim, and Arthur Laurents wrote it, from music to lyrics to book, based on an idea conceived and staged by Jerome Robbins.