People reports that Nick Lachey is set to host a new singing competition show, The Sing-Off, for NBC. The four-night series will premiere Dec. 14. Eight singing groups will compete for an Epic/Sony contract. Most striking in the age of Auto Tune, the show will require acts to perform a cappella. Lachey, a former member of 98 Degrees, notes that he previously snag a cappella in a barbershop quartet.