Viacom  today announced the forthcoming specialThe Big & Best of 2012: A Year End Celebration Presented by T-Mobile,” an unprecedented, cross-network, eight hour digital livestream event that will highlight the music, personalities and pop culture moments that defined the past year. The livestream will kickoff on 12/12/12 at 12 PM EST and be hosted HERE. The event will play out across Viacom’s digital properties including MTV.com, VH1.com, CMT.com and ComedyCentral.com, and will include eight hours of original programming and highlights spanning MTV, VH1, Comedy Central, CMT and MTV2.

“The Big & Best of 2012: A Year End Celebration Presented by T-Mobile” will be hosted by MTV News’ Sway Calloway, VH1’s Carrie Keagan and CMT’s Kourtney Hansen and will broadcast live from MTV’s famous Times Square studio and on location in music venues in New York City, Boston and Nashville. The live event will consist of live new episodes of Viacom’s signature music and pop culture series and franchises including Comedy Central’s The Colbert Report, MTV2’s Guy Code, VH1’s Big Morning Buzz Live and You Oughta Know, MTV News’ RapFix Live and After Hours, MTV Hive’s Live in Boston and MTV Buzzworthy and CMT’s Live in Nashville, Live@CMT and Concrete Country.

The special will include this year’s breakout star Carly Rae Jepsen revealing her top five moments of the year, as well as performances from rocker Grace Potter; Canadian indie rock and new wave band, Metric; indie-rock band alt-j; country duo Thompson Square; and folk duo, First Aid Kit. In addition, country singer songwriter Dustin Lynch will perform a surprise duet. More information on each artist can be found via Viacom’s artist platform. Additional performers and celebrity guests will be announced at a later date.

Starting a week prior, MTV will release a list of 18 artists with the most engaged fans and through a social media challenge narrow down the Top 7 to compete for Last Fans Standing, The Best Fans of The Year. Throughout the livestream, the 7 artists’ most passionate fan armies will compete head-to-head in a series of challenges across social media where one artist will emerge victorious. A few of the fan armies in contention are: Katycats (Katy Perry), Rihanna Navy (Rihanna), Little Monsters (Lady Gaga), TWFanmily (The Wanted), Swifties (Taylor Swift), Selenators (Selena Gomez), Directioners (One Direction), Beliebers (Justin Bieber), Barbz (Nicki Minaj), Glamberts (Adam Lambert), Hooligans (Bruno Mars), Lovatics (Demi Lovato), and Team Breezy (Chris Brown).

For more information on The Big & Best of 2012: A Year End Celebration Presented by T-Mobile,” please visit HERE.