The core of Korean music.

Competitors are given elaborate masks to wear in order to conceal their identity, thus removing factors such as popularity, career and age that could lead to prejudiced voting. In the first round, a pair of competitors sing the same song, while in the second and third rounds they each sing a solo song. After the First Generation, the winner of the Third Round goes on to challenge the Mask King, and is either eliminated or replaces the previous Mask King through live voting. The identities of the singers are not revealed unless they have been eliminated.