Eight a cappella groups from across America compete to win a recording contract; host Nick Lachey.

Pilot

Two groups leave as the competition heats up.

Big Hits & Guilty Pleasures

Superstar Medley, Judges' Challenge & Songs Of Hope

The Finale

Episode 1

Episode 2

Episode 3

The five remaining groups come together for a performance; each group sings a medley of songs by a single artist; the judges choose the contestants' next assignment.

Episode 4

Episode 5

Eight of the 16 competing acapella groups perform as the competition kicks off. Sara Bareilles joins Ben Folds and Shawn Stockman on the judging panel.

Season Premiere: Part 1

Eight more groups perform together and separately. The groups include Messiah's Men, North Shore, Pentatonix, Sonos, Soul'd Out, The Collective, University of Delaware Deltones, Vocal Point

Season Premiere: Part 2

Theme: Radio Hits (first round), 60's Classics (second round)

Group performance: "Somewhere Only We Know" by Keane

Radio Hits & 60's Classics: Part I

Theme: Radio Hits (first round), 60's Classics (second round)

Group performance: "Rhythm of Love" by Plain White T's

Radio Hits & 60's Classics: Part 2

Theme: Guilty pleasures

Group performance: "All Night Long (All Night)" by Lionel Richie*

Top 10 Groups: Guilty Pleasure Music

Group performance: "Nothin' on You" by B.o.B. featuring Bruno Mars

Top 8 Groups: Hip-Hop Hits

Group performance: Halloween medley of "This Is Halloween" by Danny Elfman, "Werewolves of London" by Warren Zevon and "Ghostbusters" by Ray Parker, Jr.

Top 7 Groups: Superstar Medleys

Theme: Rock classics (first round), Country hits (second round)

Group performance: "Wake Up" by Arcade Fire

Top 6 Groups: Rocking Out & Goin' Country

The top five groups open the show with a medley of "I Feel Good" by James Brown, "ABC" by The Jackson 5 and "Crazy in Love" by Beyonce. Later they each perform their favorite R&B hits in an attempt to woo the judges for their votes. The group that remains standing at the end of the season receives the prize of $200,000 cash and a Sony Music recording contract. Nick Lachey hosts and Sara Bareilles, Ben Folds and Shawn Stockman serve as judges.

Top 5 Groups: The Rhythm & Blues Revue

Theme: Master Mix (combining 2 songs from different artists) (first round), Judges' Choice (second round)

Group performance: Master Mix: "Bitter Sweet Symphony" by The Verve, "Hollaback Girl" by Gwen Stefani, "Baba O'Riley" by The Who, and "Last Friday Night (T.G.I.F.)" by Katy Perry

America Votes: Group Mastermixes

The final three groups perform for the last time before finding out who America voted as the country’s best a capella group.

Live Finale: Top 3 Finalists

The groups try to make a good first impression on the judges.

The Sing Off Is Back!

The nine remaining groups perform party anthems.

Party Anthems

#1 Hits

The groups perform songs they hope will please all generations.

My Generation

Movie Night

The groups perform songs chose by the judges.

Judges' Choice

The three remaining groups compete; one group is declared the winner.

Finale

A cappella groups Timothy's Gift, Melodres, the Exchange, Traces, San Fran 6 and A.Squared compete for a first-place prize of $50,000. Jewel and Shawn Stockman return as judges, and are joined by Fall Out Boy's Patrick Stump.

One Night Only: A Special Holiday Event

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.

All Episodes of The Sing-Off

All Episodes of The Sing-Off

Season 1

Pilot

Season 1 Episode 1 - Aired 12/14/2009

Big Hits & Guilty Pleasures

Season 1 Episode 2 - Aired 12/15/2009

Superstar Medley, Judges' Challenge & Songs Of Hope

Season 1 Episode 3 - Aired 12/16/2009

The Finale

Season 1 Episode 4 - Aired 12/21/2009