Photo by Brett Carlsen/Getty Images for ACM

On December 15, Lainey Wilson shocked fans by performing with Miranda Lambert in Las Vegas, releasing a new song they co-wrote.

Wilson wrote on Instagram: “Charlie’s angels but make it country (smiling angel emoji)” with photos of her and Lambert rehearsing on stage. After covering Lambert’s “Kerosene,” they performed their surprise song. Lainey told the crowd,

“This song is so, so special, and you can hear her all over it. I’m proud of the song she helped me write, and we hope you like it.”

Lambert, Wilson, and Luke Dick wrote “Good Horses.” Wilson said it was “special” to sing the song for the first time on the third night of her “Wildflowers and Wild Horses” show.

“There were a lot of highs this past week in Vegas and this is definitely one of them,” Wilson said. “We wrote ‘Good Horses’ with [Luke Dick] and when my sister [Miranda Lambert] agreed to join me for the third night of my Wildflowers and Wild Horses shows, I knew we had to add it to the setlist. It was special gettin’ to perform it for the first time for a crowd of horse lovin’, rodeo-in’, country lovin’ people like us.”