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Carrie Underwood surprised students at Andrew Jackson Elementary School during choir rehearsal in advance of their performance at the Country Music Awards Music Festival back in June.

The Eagle Honor Choir choir group, consisting of third and fourth graders from Old Hickory, Tenn., first caught the attention of the country superstar by performing her song "The Champion" in a video posted in May.

A clip uploaded to YouTube on Monday shows the 36-year-old singer popping in on a rehearsal, and the reactions from the students are priceless.

"You guys are going to be so amazing," Underwood praised the young singers during her surprise visit. "That crowd is not going to know what hit 'em."

And she was right. The choir, directed by three-time CMA Foundation Music Teacher of Excellence winner Franklin Willis, sang Underwood's song in front of 50,000 people in Nashville on June 9. They earned the opportunity to perform after receiving the CMA Foundation grant, which aims to ensure music eduction is available for all children nationwide.

The foundation has invested nearly $12 million into Nashville public schools since 2006, providing instruments and equipment to the 87,000 students within the district, according to their website.

A CMA Fest television special will air on Sunday, Aug. 4, at 8 p.m. on ABC. The telecast will be co-hosted by Kelsea Ballerini (for the third year), and Thomas Rhett (for a fourth year), alongside guest host Bobby Bones.

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The special features performances by Miranda Lambert, Luke Bryan and Blake Shelton, as well as collaborations between Brooks & Dunn, Tim McGraw and Luke Combs — in addition to Underwood herself, who will be performing with Joan Jett.

This Story Originally Appeared On People