NBC plans holiday lineup, schedules 'Sing-Off'

NBC has firmed up its holiday programming plans, including a four-night run of new reality show "The Sing-Off."

The network's a cappella singing competition features groups competing for a chance at a recording contract. The short-run series debuts Monday, Dec. 14 and will run each night at 8 p.m.

NBC has also ordered a "Saturday Night Live" holiday special clip show to air Dec. 17, plans a special "Jay Leno Show" on Thanksgiving Night featuring a military audience and will have holiday-themed episodes of its Thursday comedies on Dec. 10.