Brave Girls took on '90s K-pop on 'Immortal Song'.

On the May 1st 'Time Travel' special, Brave Girls covered Lee Jung Hyun's 1999 hit track "Wa". Though the girl group transformed it into a brand new arrangement, they still retained Lee Jung Hyun's characteristic styling and concept.

In the end, Brave Girls lost the round to Forestella, who revealed they'd appeared on the episode to meet the girl group, and it was the Yook Joong Wan Band that took the final win this episode.

Watch Brave Girls' performance of "Wa" above and the original by Lee Jung Hyun below!