On this particular episode, the two artists had the chance to collab together and performed "What Would Have Been". The song was originally on Psy's 6th album and had featured Park Jung Hyun.
The song was different from the original but IU carried out the song in an absolutely beautiful manner with her stunning voice tone. And of course, Psy did what he does best as well. His veteran presence and leadership surely helped the whole performance as a whole.
Check out the performance above.