"The Voice" season three finale

Cassadee Pope poses after winning the third season of "The Voice," on Dec. 18, 2012.

Nicholas David appears on the live finale of "The Voice," Dec. 18, 2012.

From left, Nicholas David, Carson Daly and Smokey Robinson on the live season finale of "The Voice," Dec. 18, 2012.

From left, former season three contestants Mackenzie Bourg, Julio Cesar, Dez Duron, Cody Belew and Diego Val perform on "The Voice," Dec. 18, 2012.

From left, finalists Terry McDermott, Cassadee Pope, Nicholas David wait for the results on the finale of "The Voice," Dec. 18, 2012.

From left, Cassadee Pope, Christina Milian, Christina Aguilera and Carson Daly on "The Voice."

Bruno Mars performs on the season finale of "The Voice."

From left, season three contenders Melanie Martinez, Cassadee Pope, Liz Davis and De'Borah perform on the season finale of "The Voice."

From left, Trevin Hunte, Nicholas David, Dez Duron and Amanda Brown on "The Voice."

From left, season three winner Cassadee Pope performs with Avril Lavigne on the finale of "The Voice," Dec. 18, 2012.

Cassadee Pope, Blake Shelton pose after winning "The Voice," Dec. 18, 2012.

Terry McDermott and Cassadee Pope are seen here after learning the results of "The Voice."

Kelly Clarkson performs on the season finale of "The Voice."

Cassadee Pope won season three of "The Voice."

The Killers' Brandon Flowers performs on "The Voice" finale.

Rihanna performs on "The Voice" finale.

From left, Kelly Clarkson and Terry McDermott performs on "The Voice."

Melanie Martinez performs on the finale of "The Voice."

Liz Davis sings on the finale of "The Voice."