South Korean rapper Psy will perform his global hit “Gangnam Style” at a free concert in Seoul today that is expected to draw 50,000 fans, with millions more watching live on YouTube.

 

The two-hour concert, dubbed “Seoul Style”, has been promoted as a personal “thank you” from the 34-year-old singer to his home fans, following his improbable rise to international stardom.

 

The video to “Gangnam Style,” which features Psy’s much-imitated horse-riding dance, went viral after its July release on YouTube, where it has now notched up more than 350 million views.

 

Despite being sung almost entirely in Korean, the song is currently top of the British charts and number two on the US Billboard’s Hot 100 chart.

 

The singer, whose real name is Park Jae-Sang, had pledged to dance “half-naked” at the concert if he makes it to the Billboard top spot.

 

“Clearly, Psy remains in contention for the Hot 100’s coveted No. 1 rank next week,” Billboard said on its website Wednesday.

 

“Until then, however… he’ll have to keep his shirt on.”

 

Seoul municipal officials said they would extend subway services and block off traffic from the area around the venue, Seoul City Hall, to ensure the crowd’s safety.

 

Psy returned last week from a hugely successful promotional tour in the United States that included appearances at the MTV awards in Los Angeles and on NBC’s “Saturday Night Live”.

 

In a press release, his agency said the free concert was “to return the encouragement domestic fans have been giving to Psy, regardless of whether or not he makes it to the top of the Billboard chart”.