12-year-old Beau Dermott stuns 'Britain's Got Talent' judges with 'Defying Gravity'

"Are you nervous?" Simon Cowell asked Beau Dermott on the episode of Britain's Got Talent that aired Saturday night (April 9), just before she started singing. Her response: "Yes."

Cowell seemed skeptical when the 12-year-old, who at first seemed awfully shy, announced from the stage that she would be performing "Defying Gravity" from the musical Wicked - which, unless you are as talented a vocalist as Idina Menzel, is not a song that can easily be pulled off. But even Cowell joined the entire room in a standing ovation as she beautifully hit every note.

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Judge Amanda Holden pressed her golden buzzer for Dermott, meaning she will advance straight to the live semi-finals on this season of Britain's Got Talent.

Watch the young girl with a big voice's unexpected, impressive performance below.