'The Voice's Christina Aguilera, Adam Levine, Cee Lo Green and Blake Shelton rock House of Blues

2 of 14: Adriana Louise, a 'Team Christina' contestant on 'The Voice,' performs at the NBC show's special concert to celebrate the announcement of the top 12, held at the House of Blues in Los Angeles on Nov. 8, 2012. ( Photo / Frazer Harrison / NBC)