The first season of The Sing-Off premiered on December 14, 2009.
The show featured eight a cappella groups performing popular songs live.
The winner's prize was $100,000 and a Sony Music recording contract.
[1] Nick Lachey hosted, while Ben Folds of Ben Folds Five, Shawn Stockman from Boyz II Men and Nicole Scherzinger from The Pussycat Dolls were judges.
The show ran for 4 episodes, concluding on December 21, 2009 with a live finale.