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

Slideshow posted in Photos | Friday, November 09, 2012

8 of 14: 'The Voice' coaches Christina Aguilera and Adam Levine appear at the House of Blues in Los Angeles on Nov. 8, 2012 for the NBC show's special concert to celebrate the announcement of the top 12. ( Photo / Frazer Harrison / NBC)