Cassadee Pope voted as Season 3 'The Voice' winner

Cassadee Pope, who was country singer Blake Shelton's protege on the third season of NBC's "The Voice," has won the show's competition.

The 23-year-old singer is stepping out into a solo career after performing with a band called Hey Monday. Her victory over Scottish native Terry McDermott (second place) and long-bearded Nicholas David (third place) was announced at the end of a two-hour show Tuesday.

One of the highlights of the finale was seeing all four judges/mentors take the stage to perform Green Day's "Time of Your Life." Christina Aguilera and Celo Green will be leaving the show, replaced by Shakira and Usher next season.

All three of the finalists sang duets Tuesday night with major stars. Terry McDermott peformed with Peter Frampton, Nicholas David sang with Smokey Robinson, and The Voice winner Cassadee Pope sang with Avril Lavigne.

"The Voice" has grown into a hit for NBC and was the key factor in the network's surprising success this fall. The Monday night show had 13.4 million viewers, according to the Hollywood Reporter.

The show's status was affirmed by the stream of hitmakers who performed on the finale. They included Rihanna, Bruno Mars, the Killers, and Kelly Clarkson, the first-ever American Idol winner.