Hidden Voices (season 1)

Under the versus format, both guest artists can eliminate one mystery singer each in the first two rounds, and then both can choose one mystery singer each to perform a duet with in the third round.

The winning condition implies to each mystery singer chosen by guest artist that has been performed a duet separately, if:

• One guest artist had chosen a "good singer" and another one had chosen a "bad singer"; or
• Both two guest artists had chosen a "good singer" or a "bad singer".

If one guest artist picked a good singer, he/she gets a main prize of ₫50,000,000. On the other hand, if both guest artists picked a good singer, the same amount gets splitted in half with ₫25,000,000 each. Both winning mystery singers, regardless of being good or bad, receive ₫10,000,000 each.[4]

There are seven individuals of mystery singers standing on the platform with its aliases to keep their identities concealed until stage of truth performance.

The guest artist is given some time to observe and examine each mystery singer based on their appearance. After this, a muted video of each mystery singer that reveals only 0.3 seconds of their singing voice is played as an additional hint.

Each mystery singer performs a lip-sync to a song. Good singers are miming to own voices while bad singers are miming to other's voices.

The guest artist(s) must have then 30 seconds to interrogate the remaining mystery singers before making the final decision.