Carrie Underwood Reunites With 'American Idol' Judge Paula Abdul Amid Show's Reboot

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As fans anticipate American Idol's return to TV, the show's alumni had a reunion in Nashville, Tennessee.

On Wednesday night, Carrie Underwood -- who won the fourth season of Idol -- went to see Paula Abdul perform at the Bridgestone Arena as part of The Total Package tour. The 54-year-old singer -- who was one of the original judges of Idol and remained on the show for eight seasons -- was thrilled to run into Underwood backstage.

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"So happy to reunite with the amazingly talented and equally beautiful @carrieunderwood tonight," Abdul captioned a photo on Instagram of herself hugging the 34-year-old country crooner. "So proud of your journey."

Underwood also shared the pic, writing: "Well, look who I ran into backstage at #TheTotalPackage Tour! So cool to watch her do her thing!"

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The Idol reunion comes just days after ABC announced that Katy Perry would be one of the judges when the singing show returns to TV on its new network in 2018. No other judges have been confirmed as of yet, but NBC's competing program, The Voice, recently announced that it has signed two former Idol contestants to serve as coaches for their singing series.

Jennifer Hudson -- who was a finalist on the third season of Idol -- has been confirmed to coach the upcoming 13th season of The Voice, while Kelly Clarkson -- the first contestant to win Idol -- will be a coach on season 14.

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With Clarkson and Hudson at The Voice, and Perry at Idol, the contestants of these shows aren't the only ones that will soon been in a high-stakes competition. Here is ET's look at the epic ratings battle that is expected to ensue when these programs face off against each other:

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