Little Big Town have had a big year with their song “Girl Crush,” so much so that the tune was performed at the CMT Artists of the Year show — but not by the band.

The song took on a pop sensibility with stars Adam Lambert and Leona Lewis, who performed it as a duet at the ceremony. Band members Kimberly Schlapman and Phillip Sweet were in the audience, clearly moved by the emotional rendition of their hit, but also remembering fellow member Jimi Westbrook’s sister, who had just passed away.

Lambert, an American Idol alum, and British pop star Lewis put their hearts into the performance with powerful vocals and a pop styling, ad-libbing some impressive melodies at the end. Little Big Town was honored alongside Sam Hunt, Blake Shelton, Luke Bryan and Florida Georgia Line for their successes in 2015. Schlapman paid tribute to Westbrook’s sister during her acceptance speech, and Westbrook posted a touching tribute on Instagram that day, writing:

"When I was a kid she taught me to hold my head up and be confident in who I was. That has always stuck with me. She always claimed that she wanted a little brother so bad that she prayed me into this world ... and I always believed her. As hard as we knew how, we prayed to keep her in this world with us but somehow it wasn't meant to be. My heart is so broken today and it will forever have a hole in it."

The band also posted an Instagram about the special evening, gushing about the performance and the memorable night.

“Girl Crush” received several honors at the CMA Awards this year, including Song of the Year and Single of the Year, and the band took home Vocal Group of the Year. They were also nominated for Album of the Year for Pain Killer.

See Pictures From CMT Artists of the Year 2015