'The Voice' Recap: Three's Always a Crowd as Contestants Battle On

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THE VOICE (L-R) - Adam Levine, Shakira, Usher, Blake Shelton

Who says battles on "The Voice" have to be vicious? At one point on Monday night's episode, Carson Daly called a match "The Notebook, Part Two," while Adam Levine added, "That was like watching two golden retriever puppies frolick through fields of wheat during the sunset. Cute overload -- so romantic and sweet."

Still, the sudden-death duets sent singers home, especially when they couldn't tempt another coach to steal them away from elimination (both of Levine's steals have already been used). And it's especially harder when battling against one of the season's three duos – inside the ring, three is always a crowd.

'The Voice' Recap: Contestants Battle On As Aloe Blacc, Jill Scott, Miranda Lambert Join as Mentors

For the battles, Shakira recruited Miranda Lambert in as her guest mentor, Levine called on Aloe Blacc, Usher had Jill Scott, and Blake Shelton pulled The Band Perry -- the first band to ever stop by "The Voice" as a guest mentor.

Meet the latest to move on to the next round of "The Voice" (and soon receive advice from Coldplay's Chris Martin) over at THR.com.