The Sing-OffTV downloads. All seasons on all-shares.com

"The Sing-Off" is a one-of-a-kind battle of voices that features the country's top a cappella groups performing popular songs in a way that viewers never heard them before. There's no lip-synching, back-up bands or safety net. They'll be singing for America's vote with the winner walking away with the ultimate prize -- an Epic Records/Sony Music recording contract.