KBS's "Immortal Song 2" has been gaining criticisms for the continuous 'revolving-door' issue with its idol participants. The show has aired its third episode, but the ratings seem to hover around the 6-7% mark. Many have attributed this low rating to the constant switch-ups in the cast. The first episode boasted a line-up that included�2AM's Changmin, B2ST's Yoseob, Super Junior's Yesung, SISTAR's Hyorin, SHINee's Jonghyun and IU. From the second episode, IU had dropped out and SECRET's Song Ji Eun had taken her place. By the end of the third episode, Jonghyun, Yesung and Yoseob will have left the show, with F.T. Island's Lee Hong Ki, 2PM's Junsu and MBLAQ's�G.O. acting as their replacements. Amongst the changes, only 2AM's Changmin and SISTAR's Hyorin have been the constants. With criticism ringing in again, the PD has addressed this issue once more,�"The show may be lacking consistency (cast members) but it can give a sense of freshness to the viewers." The PD added, "The idols have a lot of overseas work and they can't cancel them for just one TV program. There will be no more than 1-2 member changes each time, so it won't be a big problem." Meanwhile, 4minute's Jiyoon has joined the show to replace SECRET's Ji Eun, who is going to Japan for promotions. The PD remarked, "Jiyoon is a hidden jewel in 4minute." Ji Eun will be back on the show around September, after SECRET concludes their Japanese promotions. The upcoming episode, therefore, will see performances from 2PM's Junsu, F.T. Island's Hong Ki, MBLAQ's G.O., 2AM's Changmin, SISTAR's Hyorin, and SECRET's Ji Eun. Source: Money Today, 10 Asia, and Newsen via Nate