Having recently performed at the '2011 Jisan Valley Rock Festival', it looks like 2AM's Jinwoon couldn't wait to rock out on stage again. On August 10th, Jinwoon tweeted the below photo saying, "YB's show. Can you have another show? It was so much fun. Rock & Roll!!" The photo was taken on August 6th at a club in Hongdae, Seoul�during a show featuring YB (Yoon Do Hyun Band) and the British rock band Steranko. It was said that Jinwoon attended the show as an audience member, but made an impromptu guest appearance on stage during the last song of the concert and proceeded to take off his shirt during the performance, adding to the excitement of the show. Netizens responded to the photo with comments like, "Wow it looks so exciting!", "Rock and roll baby", and "Your six-pack is always shining no matter when or where it is". Source + Photo: Star News via Daum