Why are only three members of g.o.d. performing for 'Music Bank'?

g.o.d.'s Kim Tae Woo, Son Ho Young, and Danny Ahn will stand together once more on stage after a 5-year hiatus. On April 22nd, g.o.d. will give a special performance of their hit song "Lie" for the 600th episode of KBS 2TV's "Music Bank". Unfortunately, Park Joon Hyung (who's currently working in the States as an actor) and Yoon Kye Sang (who has switched into the acting field and is currently shooting for the upcoming MBC drama, "The Best Love") will not be present, leaving Danny Ahn, Son Ho Young, and Kim Tae Woo to represent g.o.d. for this reunion stage. Upon hearing the news, fans began to express their curiosity over a certain element. They understood that Park Joon Hyung would not be able to participate since he's in America, but they could not understand why Yoon Kye Sang could not share the stage. A representative from Yoon's agency explained, "We never heard that g.o.d. will be reuniting at 'Music Bank', and we were never given an offer to appear. Even if we were, he wouldn't have been able to participate because of his drama shooting. There is no discord between him and the other members." Source: Newsen via Nate