The fourth season of the Vietnamese television mystery music game show Hidden Voices[1][2] premiered on HTV7 on 27 July 2019.
Despite the linear airings ended on 2 November 2019, it was later extended by 11 additional episodes until the formal conclusion on 18 January 2020.
[a] Under the "battle format", two opposing guest artists eliminate one singer each during the proper game phase, and then remain one singer each to join the final performance.
At the end of a game, the following conditions for winning mystery singers chosen by opposing guest artists, depending on the outcome of final performances, if: If the last remaining mystery singer is good, the guest artist wins đ50,000,000; in case of a tie, the main prize is halved, leaving them with đ25,000,000 each.
Both winning mystery singers, regardless of being good or bad, get đ10,000,000 each.