It's not often that there's a duet on "The Voice," but this duet was even more spectacular. The judges were left confused when they had their backs to the two sisters, thinking at first that they were just listening to one singer on the stage. Adam Levine said he was left completely shocked to hear harmonies after believing that he had found one amazing singer. Be honest with yourself when you listen back to Whitney & Shannon and share just how many voices you hear in the beginning.

The sisters hadn't sung together in a year before "The Voice" 2016

You'll be forgiven for believing that the two sisters had been singing together for their whole lives. It turns out that both have lived on opposite sides of the country and haven't sang together for at least the last year. However, they have wanted to pursue this dream for so long that they just had to go in for "The Voice" audition together.

It all paid off, too. They had all four judges turn around, leaving them with a very difficult choice to make.

Just who did the two choose as their coach for the rest of the singing competition?

Whitney & Shannon blow the minds of the judges

Adam Levine said that his mind was completely blown after hearing the sisters sing. He just had to turn around, knowing that the harmonies could either work perfectly or be absolutely terrible. There is no in between with this sort of singing and the sisters certainly pulled it off.

Blake Shelton realized that the version of "Landslide" the sisters were singing was the Dixie Chicks' version and commented on their country sound. He wanted to add them to his team.

Who did the sisters end up choosing? The four judges were left nervous as the sisters discussed in front of them who they would choose. In the end, they had to go with Alicia Keys, who was ecstatic at the news. She couldn't help but jump up and run to the sisters to hug them.

That's the blind auditions over with now for "The Voice" 2016 on NBC. This Tuesday will see a highlight of all the best performances before the battles take place next week. So go on, how many voices did you hear in the beginning of this performance?

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