Chris Stapleton and Miranda Lambert Perform 'Maggie's Song' During 2021 ACM Awards

Fans got a surprise on Sunday night when Miranda Lambert performed with Chris Stapleton during the ACM Awards, filling in for Stapleton's usual stage partner, his wife, Morgane. Lambert and Stapleton duetted on "Maggie's Song," an emotional track about the loss of Stapleton's family dog that appears on his latest album, Starting Over.

The duo performed at The Bluebird Cafe, sitting in the round as Stapleton strummed an acoustic guitar and Lambert joined him on vocals. The song's lyrics document Maggie's life with the Stapleton family, from the moment they found her in a shopping cart in a parking lot to the day they buried her. "Run, Maggie, run / With the heart of a rebel child," the chorus reads. "Oh, run, Maggie, run / Be just as free as you are wild." Lambert is a noted animal lover with numerous pets of her own, making her the perfect choice to join Stapleton on the tearjerking song.

Ahead of the show, Stapleton used Instagram to share a photo of Maggie with his followers. "Sweet Maggie," commented Morgane, who missed Sunday's show due to a "prior doula commitment." In a virtual press room after the awards, Stapleton shared that his wife was "on baby watch" for her sister, who may have been in labor at that very moment.

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"Missed her very much tonight, but I was so happy that Miranda agreed to fill in kind of last minute," he said. "I think my sister-in-law's in labor right now. She may be on her way to the hospital, I'm not sure. My wife is kind of on baby watch. And for once not her own baby. But it's been an interesting night tonight. So lots to celebrate and the awards are just part of it."

Along with his performance, Stapleton picked up some hardware on Sunday when he was awarded Album of the Year for Starting Over, which he can't wait to play live for fans. "There's nothing I'm looking forward to more than seeing the faces of people out in the crowd and hearing them sing back to me and hopefully hearing some of these new songs sung back to us because that's when music really gets life to me," the 43-year-old explained.

"I can write a song and I can record a song and I can sing it in the room by myself, but it doesn't mean a whole lot until it goes out to somebody out in an audience or somebody sitting home listening or somebody listening in their car, that's when it gets meaning," he continued. "And so for me, that's the thing I'm most looking forward to, it's to get back out into the world and see people and have played music with them and enjoy that experience that we have together in a room playing live music."