More than 80,000 people in Seoul, South Korea caught Psy fever as they performed the dance routine to his international viral hit "Gangnam Style" in unison.
The audience showed up to watch Psy, in his hometown, at his concert Thursday at the Seoul City Hall plaza.
"Psy, Psy," they crowd yelled as he appeared onstage, said The Christian Science Monitor. CSM said Psy, whose real name is Park Jae-sang, performed for two hours at the free concert.
"I knew one of these K-pop stars would hit the world," Psy tells his cheering audience, "but I didn't know it would be me," he told the audience.
The article said Psy promised to have a free concert at the plaza if his hit charted on Billboard.
"Gangnam Style" is about the rich and luxuries life of the Gangnam District in South Korea.
Psy set a Guiness World Record last week as his video became the most "liked" video on YouTube, reaching 3.5 million likes. He also holds the title as the only South Korean artist to have song go to number 1 on iTunes.
"Gangnam Style" debut July 15 and quickly went viral. YouTube published statistics showing that within two months, "Gangnam" has increased to an average of more than 6 million views per day.