South Korean singer PSY speaks at Harvard University's Memorial Church in Cambridge, Massachusetts May 9, 2013.[Photo/Agencies]

South Korean rapper Psy said he "partied hard" when his dance number drew its first 10 million views on YouTube last summer. Little did he know "Gangnam Style" would become the most-viewed video in the online service's history, with a global following and nearly 1.6 billion views as of Thursday.

Photos: Psy speaks at Harvard University

"I partied hard to celebrate 10 million views!" Psy told about 1,000 people at Harvard University on Thursday evening, as he recalled his reaction when the song took off, making him a cultural phenomenon and leading to meetings with Los Angeles record producers.

"This is so unrealistic!" he recalled thinking.

Formally dressed and speaking in sometimes-halting English, Psy spoke for more than an hour and occasionally lapsed into signature dance moves such as grasping the reins of an imaginary trotting horse.

Psy's talk was partly a homecoming as he recalled his days as a student in Boston in the mid-1990s. But it was also a seminar about the star's surprise worldwide cultural appeal and the economic influence of East Asian culture.

Harvard professor Alexander Zahlten introduced Psy, whose real name is Park Jae-sang, as a global figure who has shown the ability of Korean music stars, video-game programmers and other entertainment figures to find overseas popularity through Internet channels.

"He's a global citizen, and in turn influences people all over the world," Zahlten said. "He's deeply connected to digital culture."

After "Gangnam Style" set records, the video for Psy's follow-up song "Gentleman" received more than 20 million hits in the first 24 hours after its release last month, easily beating the previous record of 8 million views for Justin Bieber's "Boyfriend" in the first 24 hours.

Psy, 35, told the audience at the Ivy League school that music trumps national divides. "Music makes everyone united," he said. "Something beyond language." At some performances, he said, "I'm so proud. The crowd doesn't know what the lyrics are about, but they look so happy!"

Later he said the word for "style" conveyed similar meanings in all languages, and that he wrote the lyrics for "Gentleman" hoping they would find a similar worldwide resonance. "Really , it was linguistics," he said.

Psy also poked fun at his own less-than-stellar academic record. He said his nickname in college was "WWF" for his grades, "withdraw, withdraw, fail." He said he kept thinking big and poked fun at his robust midsection.

"I dreamed someday, some Korean artist would be well-known in the US," he said. "I dreamed about it but didn't dream that was me, because as you see I have a very special body type."

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