What a difference two months make. For the past dozen years, PSY has been a popular rapper and entertainer in Korea. Then in July, he uploaded his video for “Gangnam Style” on youtube.com, and the song went viral to the tune of more than 161 million views. Katy Perry, Britney Spears and Nelly Furtado tweeted about the song to their followers. “Gangnam Style” charted at No. 1 on the iTunes Music Video Charts, topping Perry and Justin Bieber and cracked the Billboard Hot 100 chart at No. 64. PSY is now represented by Bieber’s manager, Scooter Braun.