Yoo Jaesuk is quite powerful in K-entertainment and his peculiar music style does not really help KPop, although fortunately foreigners are ignoring his antics now.
His latest attempt is MSG Wannabe.
Who are part of it?
Ji Sukjin - Yoo Jaesuk's toady at Running Man
Kim Jungmin - a rock-ballader popular in 1996
KCM - a ballader somewhat popular in mid-2000s, although mostly as a staple in show programs
Simon D - an ex-exec in Jay Park's company
Park Jaejung - Winner of Super star K5 but mostly an OST staple after that
Wonstein, a rapper
Lee Donghwi and Lee Sangyi - actors
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Ji Sukjin tried singing in 1992 but was mostly in entertainment after that. (He released a song "I know" at the same time Seotaiji released the super hit with the same name, which basically made Ji Sukjin give up his singing dreams and enter the showbiz instead)
Kim Jungmin's heyday of 1996 is probably too distant for most Kpop fans
KCM was never that popular outside of show programs
Simon D really did not promote for quite a while too
Park Jaejung is mostly known as an OST singer.
I will spare words on the rest since the actors obviously do not belong there and I don't know too much about Wonstein.
Other than maybe Simon D, none of them are really relevant in the narrative of KPop. Jungkook was not even born when Kim Jungmin had his heyday.
What is that?
Hyori and Rain, I can understand. At least they were super popular. However, these people?