A brand-new masked bunch of celebrity singers face off against one another in dazzling head-to-toe costumes; a singer is unmasked. — These masked celebrities have stars on the Hollywood Walk Of Fame, have sung at NFL Super Bowls and have a combined 281 million record sales between them. Can you guess who is behind the mask?

Six more contestants are introduced, and the panel try to guess the identity of Crocodile, Baby Alien, Seahorse, Whatchamacallit, Serpent and Gremlin. At the end of the show, one singer is unmasked and sent home.

Contestants return for the Group A playoffs and their second performances for their chance to progress in the competition.

The contestants return for the Group B playoffs and their second performances of the season.

The final group of celebrity contestants take the stage for their first performances of Season 4.

The Group C contestants return for their second performance of the season.

The final three singers from group A take the stage for their final chance at the super six; one singer is unmasked.

The remaining four singers from "Group B" compete for a chance to advance, but with room for only two in the "Super Six," two celebrities must be unmasked.

Get an extra helping of America's favorite guessing game, when the final three singers from "Group C" compete for the final two spots in the "Super Six".

The final three singers perform never-before-heard holiday songs, with all-new animated clues; the already unmasked celebrities join together to perform their favorite holiday jingles.

A look back at the best moments and performances from Season 4.

The three finalists perform one last time before all are unmasked and one singer takes home the trophy.