Featuring the country's best a cappella groups performing popular songs like you've never heard them before. There's no lip-synching, backup bands or safety net. They'll be singing for America's vote, with the winner walking away with the ultimate prize - a Sony Music recording contract and $100,000.

Release : December 14, 2009

Website : http://www.nbc.com/sing-off

Total Eps : 28 / 120 minutes

Total Season : 6

Rating : 4.67