Blake Shelton and his costar judges on NBC’s The Voice didn’t know what to expect when they were told they were meeting host Carson Daly’s Austrian counterpart, but it surely wasn’t this. Actor and performer Neil Patrick Harris decided to play a little prank on the celebrity judges for his new show Best Time Ever, dressing up as the host of the show’s Austrian version to learn more about how it’s done in the U.S.

It's clear from the look on Shelton and Adam Levine’s faces they are taken aback by "Jergan"'s oddities. The fake Austrian host asks Gwen Stefani and Pharrell Williams questions about the show, and proceeds to tell Levine he’s his favorite judge. Levine seems pleased until "Jergan" changes his mind and tells Shelton he’s his favorite instead. All parties are confused as they walk away, muttering and laughing about how strange it was. But they hadn’t heard the half of it.

After the show begins, Shelton and the others take their seats in the iconic red chairs, backs to the stage, and await the next Blind Audition. Little did they know, “Jergan” is back and ready to blow them away with a passionate, albeit nasal and pitchy, performance of “And I am Tellin' You” from the movie Dreamgirls, originally sung by powerhouse vocalist Jennifer Hudson.

The judges exchange confused and somewhat disgusted looks as “Jergan” finishes, none of them turning their chairs around to claim him for their teams. Their shock at seeing the host standing onstage is soon overshadowed by the big reveal, as Harris finally lets them in on the joke.

Stefani comments that she has notes on his performance, and Shelton chimes in.

“I have notes, too, but I changed it now that I found out what you did and it just says, ‘you’re an a--hole,'” he explains, laughing.

Watch the whole charade in the clip above, then catch Shelton and the other judges on the ninth season of The Voice, which premieres Sept. 21.

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