Transcript for Psy's 'Gangnam Style' Dance Takes Over 'GMA'

Thank you, george. We're very excited for something coming up. We've been waiting for this all morning. It's the dance from the smash hit music video that's taken over the world. "Gma" is going "gangnam" right now. Don't pretend like you don't know what we're talking about. A blockbuster video by south korean rapper, psy. We're going to hear from him. We're not exactly sure. You want to say -- here's how it's actually said. One of our great "gma" staffers sons, she does the books for us. She told us how to say it. We solved the mystery. It's pronounced "gangnam." Say that again. Gangnam. The "g" sounds like a "k." Thank you. We have a few surprises for you just ahead. First, here a look at why "gangnam style" has turned into a phenomenon. Three magic words launched south korea's psy on a meteoric rise to fame. ♪ Hey, sexy lady ♪ I've done this 12 years in korea. I'm a rookie now. Local at daytime and crazy at night. That's "gangnam style." Psy posting his youtube video in july. And before you could say -- gangnam style. Reporter: It was going gangbusters. Not to mention a flood of parodies and tributes. Since psy was riding his invisible horse to the red carpet. I can dance cheesy. I want to do it again. Reporter: The vmas. And tmz, where he stopped to give the paparazzi a quick lesson. One, two, three, four. I can't really do that. Reporter: But the dance is going even farther. On top of all, kids, college students, and flash mobs, "gangnam style" turned up in nfl end zones, baseball, concerts, and right here on "gma." Come on, girl. Psy, come on out. Reporter: And on monday, ellen DeGeneres surprised britney spears with a choreography lesson from psy himself. Cue the music. One, two, three, four. Reporter: All of it far beyond psy's wildest imagination. I was just thinking to make a huge hit in korea, that was my only purpose. Reporter: So, with psy playing in front of huge crowds and the whole world going "gangnam style," where the viral dance epidemic go next? Oh, look. Well, there you go. George did do it. See? We knew. Here we go. "Gangnam style." It's taken over the world. It's taken over the interwebs. And it's time to take over times square. Is everybody ready? "Gangnam style." Here we go. ♪ ♪ ♪ ♪ ♪ ♪ ♪ wow.

This transcript has been automatically generated and may not be 100% accurate.