In the midst of the highlight of his career, Psy's "Summer Stand: The Drenched Concert" featured top star guests like 2NE1, Sung Si Kyung and Noh Hong Chul.

Yesterday (August 11), singer Psy performed at his "Summer Stand: The Drenched Show Concert" at the Seoul Olympic Gymnasium with 30,000 fans cheering for him in the audience.

One of the reasons Psy's concert was such a big hit was because of the special guests that appeared at the concert. Each surprise guest delivered a passionate performance and gave it their best as though it was their own concert.

The first surprise guest was 2NE1 from the same entertainment agency YG. Psy began to sing his song "What Should Have Been" when Bom appeared for the female part of the song. The audience went crazy with excitement when they saw the 2NE1 member, Bom. When Psy excused himself from stage after telling the audience he needs to go change his attire, 2NE1 appeared on stage to perform "I Am the Best" and "I Love You."

For the song "Shake It" comedian Noh Hong Chul appeared on stage with Psy and delivered a crazy and comedic performance. Even though Noh Hong Chul isn't a singer, his comedic and powerful dance moves made the crowd go wile with excitement.

The last surprise guest was Sung Si Kyung, who stated, "The stage is so big. I feel this every time I come here. It's so different from my own concerts. My voice isn't in a very good condition right now from cheering for the Korean soccer team and filming '1 Night 2 Days' but I will give it my all." After singing his song "You Are My Spring", he revealed, "This is so unfamiliar to me. I hope all of you that have been partying this whole time will watch my performance as a break" and brought laughter to the audience.

The audience received much more than they ever expected with Psy's powerful performances and the surprise guests who helped make a lasting impression of Psy's concert.