Some of the best speculative fiction has achieved its impact by creating a world identical to our own except for a single noticeable difference, be it absence or presence. What courses might society have taken if, for example, we could read minds? Or had lost the Second World War? Or had just recently intersected with an alien civilization?
West Side Story falls into this tradition: it posits a dystopian America in which menacing street gangs control New York, and violence (both physical and emotional) and repressed homosexual attraction are sublimated into spontaneous, flamboyant eruptions of singing and dancing.
