Veteran ballad singer�Sung Si Kyung released some teaser photos recently for his impending comeback concert. On May 12th, Sung Si Kyung's agency revealed a few photos in order to announce his upcoming 7th album release concert on May 28th and 29th. This marks his first music-related activity since his military discharge in May 2010. Guests for this upcoming concert include Park Jung Hyun (a.k.a. Lena Park), IU, and his 'mentor' Yoonsang. Kim Jang Hoon will also be serving as the general manager of his concert. Many anticipate that this concert will be another high-class event like his 'First Time in 2 Years, You...' concert from last year. Ticket sales for this concert have been hot, as its VIP passes have already sold out. Source: Newsen via Nate