Dancing. Most musicals have it, and if they don't, they might not qualify as musicals. People who aren't fans of the genre often grouse about it, since most movie characters don't suddenly burst into elaborate choreography in the real world. (They don't fight off alien invaders or get bitten by radioactive spiders either, but no one seems to have a problem with that.)

West Side Story has some of the toughest and most elaborate dance moves you'll ever see. What's harder to spot is the way dance can tell a story: to move the narrative forward and show us the relationship between the characters. Take the "America" sequence, which shows the competition but seductive playfulness between the Puerto Rican men and women. And you won't see the narrative power of dance any more clearly than in the opening number, which explains the whole backstory of the film without a single line of dialogue.

Look closely.

We start off with the Jets: kings of the hill and moving through "their" streets in perfect sync. They run into one guy alone, Bernardo. and since he's just one and they're ten, they get to push him around. Soon enough, he's joined by other Puerto Ricans who have gotten the short end of the Jet stick too.

We see this in dance: Bernardo moving alone, before being joined by two other men, who then dance and perform in time with him. They start hassling lone Jets, but that doesn't last too long since three still won't beat ten. Happy times for the Jets still.

Then one day on the basketball court, Bernardo snags their ball… and now he's got four dance partners instead of two. The Jets still have the edge, but as Bernardo and his Sharks step away, once of them trips a lone Jet. The rumble is small—and keeps awfully good time with the music—but it's clear the Sharks aren't going to take it anymore.

More dancey-singey fights follow, each one getting bigger and bigger until we come to the real start of the story. The Sharks aren't small time anymore, and they're giving as good as it gets.

Two sides with a blood feud. Neither of them able to shut down the other. Bad blood just boiling out of their ears. And by the time Schrank and Officer Krupke break it up, we have been fully briefed on the situation—all without any dialogue and shown solely through the stylized movement of the actors.

The dance at the gym sequence accomplishes the same stuff. We see the competition, the cultural differences, the youthful energy that will explode in violence later. Here, the violence is sublimated into dance.

Let's see the Avengers pull that off.