AceShowbiz - Brandi Carlile and Maren Morris made their debut as The Highwomen at Loretta Lynn's birthday gig in Nashville, Tennessee on Monday night, April 01.

The country stars put the supergroup together with Amanda Shires and Natalie Hemby and decided Loretta's bash would be the perfect time to hit the stage for the first time.

Backed by Dave Cobb, who is producing the quartet's upcoming debut album, and Jason Isbell, the ladies belted out a cover of Kitty Wells' classic "It Wasn't God Who Made Honky Tonk Angels".

Carlile told Rolling Stone at the bash that the recording of her new group's first album will feature in an upcoming documentary about the band, which was inspired by 1980s and 1990s country supergroup The Highwaymen, made up of Johnny Cash, Waylon Jennings, Willie Nelson, and Kris Kristofferson.

"We are making a four-part documentary and a record," Carlile said. "I re-wrote the original Highwaymen song with Jimmy Webb, with stories of women who died in protest. We wrote a bunch of country songs, Dave Cobb is producing the record and we are saying, 'We are country artists', and we are going to ask they include us. And if they do or don't, either way it will tell a story about feminism in rural American music."

Meanwhile, The Highwomen's upcoming debut album will feature guests like Janelle Monae and Sheryl Crow.

"It's turning into a movement in Nashville," Carlile added.

Loretta Lynn's 87th birthday tribute concert also featured performances by Garth Brooks, Trisha Yearwood, George Strait, Keith Urban, Miranda Lambert, Alan Jackson, and Kacey Musgraves, among others, while Loretta belted out her hit "Coal Miner's Daughter".

Urban provided one of the night's non-musical highlights when he jumped out of the birthday girl's cake, fulfilling a promise he made in January when he signed up to play at the gig.

Lynn will turn 87 on 14 April.