In my opinion the absolute best part of the film production of West Side Story is the 5minute long opening sequence that transitions from an Overture of all the songs in the movie played over an abstract of Manhattan — with each song representing a different color and mood — to that abstract becoming a reality in the vision of Manhattan. The camera then pans over the vastness of the city, to the sound of a distant din of traffic, horns honking, planes landing, ships horning. Then a whistle, and in the vastness, in the expanse of cultures, religions and identities the view focuses on a playground. And the story unfolds.
It is simply one of the best cinematic introductions ever put on film.