Miranda Lambert will sing a medley of her greatest hits at Sunday night's (April 7) ACM Awards, as well as a collaboration with George Strait. Video footage of her rehearsal (seen above) shows Lambert singing her hit "Mama's Broken Heart," which will likely be included in her performance.

"I'm singing a medley of my own songs from like the best over a decade, I guess milestone hits for me and then I get to sing with the King, George Strait," Lambert says.

This isn't the first time Lambert has performed with the King Strait, and it never gets old — and she certainly doesn't take such an honor for granted. "That's always ... I get a little glossy-eyed every time I sing with him, so I'm excited," she admits, laughing.

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For her, the ACM Awards are more than just an awards show.

"ACM is such an important part of country music," Lambert says. "I mean, for one thing, it's the place we all come and celebrate and get to be together and reunite with old friends, new friends but we're celebrating country music as a family cause that's what we are."

Lambert is nominated for Female Artist of the Year, as well as Music Event of the Year for her collaboration with Jason Aldean on "Drowns the Whiskey." The 2019 ACM Awards are set to air live from the MGM Grand Garden Arena in Las Vegas on Sunday, April 7, at 8PM ET on CBS. Reba McEntire will host.

This week, Lambert announced her 2019 Roadside Bars and Pink Guitars Tour that will be traveling the United States this summer. She will have support from Pistol Annies, Elle King, Caylee Hammack and Tenille Townes on select dates.

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