Judges Katy Perry, Lionel Richie and Luke Bryan will all perform, as will season four winner Carrie Underwood, who has been serving as a mentor on the program.
Leah Marlene, Noah Thompson and HunterGirl were good enough to impress the judges all season long, and in fact, it's fair to say the trio got them excited from the very start.
HunterGirl, who Bryan called his "favorite female country voice I've heard" in five seasons on the show, is considered the favorite to win.
"I don't feel like, I don't know, I don't know how I got here," she said. "But I'm so happy I made it to this point."
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If she prevails, she'll be the first female country singer to win since Underwood launched her career on "Idol."
The star has been mentoring Thompson this season, and his place in the top three is all the more remarkable because he overcame COVID.
"It took a big toll," he said. "I almost felt like I couldn't breathe, and my throat was killing me, so it just sort of broke my heart almost."
As for the third finalist, Perry said Marlene looks and sounds like an angel.
"I'm just celebrating," she said. "That's my mood going in. I'm in shock that I'm here still, and I'm just going in to celebrate and just savor every last moment because we've all been together for so long."
Win or lose, they all call their time on "American Idol" a life changing experience.
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