Blake Shelton, Christina Aguilera Duet on ‘The Voice’ (WATCH)

It takes a brave soul and powerful pipes to sing with Christina Aguilera, and Blake Shelton pulled it off like a champ on Monday's episode of "The Voice." The fellow coaches on the hit NBC show opened the broadcast with their new duet, "Just a Fool." Watch their performance of the soaring ballad below.

"He's my big brother," the pop icon says of the reigning CMA Entertainer of the Year, "and I'm the closest to him of all the guys. Blake is just a rockstar; he's great. He's so playful, so fun and down to earth. He's got a lot of heart."

"Just a Fool" is featured on Christina's new album, Lotus.

Also on Monday's episode of "The Voice," Team Blake member Cassadee Pope sang the touching ballad, "Over You," co-written by Blake and wife Miranda Lambert. Watch a video on her tearjerking performance in the second video player below.