Usher, Shakira Usher, Shakira

Future Voice contestants will be in for a big surprise when those red chairs turn around. Usher and Shakira have signed on as new coaches for the fourth season of the singing competition, NBC confirmed Monday.

Usher, 33, and Shakira, 35, will replace CeeLo Green and Christina Aguilera, who are taking the next cycle off to work on other projects. Both are expected to return for Season 5.

"We are thrilled to welcome Usher and Shakira to The Voice. The addition of these popular iconic artists continues the tradition established by Christina, CeeLo, Adam and Blake," NBC Entertainment Chairman Bob Greenblatt said in a statement. "Doing two back-to-back cycles of this show requires a tremendous amount of time, and we are happy to accommodate the commitments made by Christina and CeeLo. The participants on our show benefit from our coaches' expertise and their continued success in the music business allows for significant new contributions to the contestants when they return."

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Aguilera, 31, is leaving to focus on promoting and touring in support of her upcoming album, Lotus, which hits stores in November. "By pursuing my first passion of music during the break, I am also able to come back and offer even more to my team on The Voice in the future," she said. Meanwhile, Green, 38, will have his hands full working on his upcoming solo album, his new Goodie Mob album, a Las Vegas residency, a new memoir and a new TV comedy he is developing with NBC. "Mi casa es su casa," he said, welcoming the new additions to the coaches panel.

"Having award-winning artists as coaches means they need to be able to tour. Whether in the red chair or on tour, our coaches have their chairs for life," executive producer Mark Burnett said. "This is exactly why, after three seasons, we needed to allow them to rotate out so they can get on the road amongst their fans. Meanwhile, we're incredibly excited to have singular artists like Usher and Shakira joining the fold."

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Now the only question is which coach will get to have a pet mascot for the next season? (Might we suggest a fuzzy and easily transportable hamster?) The big question is whether the new panel of judges would be able to match the chemistry of the original coaches.

The Voice airs Mondays and Tuesdays at 8/7c on NBC. Are you excited to see Usher and Shakira on The Voice?