Seoul: South Korean rapper Psy said on Friday he would release the highly-anticipated follow up to his global hit "Gangnam Style" in April, and hold a large concert in Seoul to mark the occasion. Psy, sporting his signature sunglasses, announced the planned release in Korean and English in a video uploaded to YouTube which featured subtitles in six languages including Chinese, Thai, Spanish, French and Portuguese. "April 2013 is a new single, worldwide all at the same time. And I'm gonna do a concert ... you can see it live, on YouTube. Just for you," he said before launching into new dance moves for the remixed version of "Gangnam Style" Tickets for the concert titled "Happening" will go on sale on March 11, his agency said, adding the event will feature the new song as well as his past hits. The 35-year-old star, whose real name is Park Jae-Sang, was pushed to global stardom after "Gangnam Style" -- a satire of luxurious lifest...