The Gangs (Symbols)
The Jets and the Sharks each represent the family unit. The gangs offers a sense of identity and protection that is usually associated with family. The gang members' actual families are largely absent and they feel somewhat left out to dry by polite society, and so they have formed their own cohesive structures to take care of them and give them a sense of purpose. The gangs are therefore symbols of family units.
The Gun (Symbol)
The gun that Chino uses to kill Tony is a symbol for violence and revenge, a lethal weapon in the hands of a child. When Maria picks it up and delivers her impassioned monologue about the hate that the community has allowed to develop, the gun becomes a symbol of both her desperation and the hatred that she has learned from the neighborhood. It symbolizes all the misguided prejudice and fear that has driven the two gangs apart and left a trail of bodies in its wake.
Something's Coming (Motif)
Tony’s first solo number, “Something’s Coming” becomes a kind of thematic motif for him. Tony is overwhelmed by the intuition that his life is about to change, and he sings:
“Something's coming,
I don't know what it is,
But it is
Gonna be great!”
Tony is sure that something is going to make his life different, something just "around the corner." When he meets Maria at the dance, she seems to be the "something" he's been waiting for, but they still have the tensions of the neighborhood to contend with, and they must hold out hope that going somewhere else will allow their love to flourish. Tony's belief that change is imminent is an emotional motif, the hunch that keeps him going.
The Wedding (Symbol)
When Tony visits Maria in the dress shop where she works, they stage a pretend wedding with the mannequins, with Maria dawning a veil from the shop. The wedding is completely fake, as they are the only attendees and there is no legal action taken, but it takes on a dimension of reality as Maria and Tony get further into it. They get wrapped up in the fantasy of it, and the wedding becomes real because of their belief in it. The wedding represents the lovers' deep love for and commitment to one another as well as their understanding that it can only exist in a fantasy world. They must sub in mannequins for their actual parents, who would never approve of the union.
Romeo and Juliet (Allegory)
The entire film is a fairly close reinterpretation of Romeo and Juliet and the allegories contained in Shakespeare’s play.
Maria and Tony are the obvious stand-ins for Romeo and Juliet, the characters representing purity, youth, and young love. Tybalt killing Mercutio is represented by Bernardo killing Riff, which leads to Tony killing Bernardo, just as Romeo kills Tybalt in Shakespeare's version. Even the obstruction of Friar Lawrence from informing Romeo that Juliet is not really dead is represented in West Side Story, when Anita falsely leads Tony to believe that Maria has been killed, which directly leads to Tony’s death.
Romeo and Juliet is a story that represents how the passion of young love cannot survive the political squabbles of the adult world, even at its most idealistic. The tragedy of the play—the two lovers dying in each others' arms before they have even reached adulthood—symbolizes the ways that adult rivalries poison the innocence and good faith of youth. Just as the Capulets and the Montagues cannot put their differences aside to make room for the romantic love shared between Romeo and Juliet, the gang rivalry between the Jets and Sharks prevents Tony and Maria from reaching that "Somewhere" that they dream of finding together. As a reinterpretation of Romeo and Juliet, West Side Story is an allegory for the ways that adult divisions and animosity ruin the purity of youth and romantic innocence.
