
Season 4 (2013)
The fourth season of The Sing-Off returned with the number of a cappella groups competing decreased from sixteen back to ten, resulting in a new format. Nick Lachey remained as host for the new season, with Ben Folds and Shawn Stockman returning as judges. New to the judges' table was Jewel, who replaced Sara Bareilles. A group was eliminated from the show each week in a new feature called the "Ultimate Sing-Off," where the two groups ranked lowest at the end of each episode would compete by singing the same song; the groups take turns alternating verses before ending the song singing together. Also, unlike previous seasons, the winner was chosen by the judges instead of by the general public.
Episodes: 7
Star Cast: Shawn Stockman , Ben Folds , Nick Lachey , Jewel ,
Episodes List

Ep.1 The Sing Off Is Back!
Air Date: 2013-12-09
The groups try to make a good first impression on the judges.

Ep.2 Party Anthems
Air Date: 2013-12-11
The nine remaining groups perform party anthems.

Ep.3 #1 Hits
Air Date: 2013-12-12
Eight groups perform their favorite hit.

Ep.4 My Generation
Air Date: 2013-12-16
The groups perform songs they hope will please all generations.

Ep.5 Movie Night
Air Date: 2013-12-18
The groups perform songs from movies.

Ep.6 Judges' Choice
Air Date: 2013-12-19
The groups perform songs chose by the judges.

Ep.7 Finale
Air Date: 2013-12-23
The three remaining groups compete; one group is declared the winner.