Eric ChurchandMorgan Wallentooktheir friendshipto the spotlight in Nashville this week when they surprised VIPs at an opening party forJustin Timberlakeand restauranteurSam Fox’sThe Twelve Thirty Clubwith a hit-packed mini-set.

Throughout the night, the crowd included fellow country singersJake Owen,Jessie James Decker,Jon PardiandChase Riceas well asKid Rockand Timberlake’s *NSYNC bandmateChris Kirkpatrick.

Church, 44, andZac Brown, 43, were among the night’s scheduled performers. Church entertained with cover songs including “Pour Some Sugar on Me,” “Tiny Dancer,” “Danny’s Song” and “Space Cowboy” before closing with his “Drink in My Hand.” Brown took over with covers of “Gin and Juice,” “Sexual Healing,” “Leader of the Band” and his hit “Colder Weather.”

Zac Brown.Jason Bihler

Zac Brown

The crowd packed in front of the stage dispersed before Church and Wallen, 28, shocked the audience and took the stage as an acoustic duo.

“This is just one of my favorite songs I’ve ever got the pleasure to sing,” Wallen said before “Sand in My Boots.”

Church, sans his trademark aviator sunglasses, stood beside him grinning like a big brother, then joined him on the song’s chorus. Wallen started to take off his guitar, and Church encouraged him to strap his instrument back on.

Eric Church.Jason Bihler

Eric Church

Wallen launched into “Silverado for Sale” as Church clapped heartily and said, “Yeah.”

Church jumped in for the spoken word part of the song. The men bumped fists at the end.

The crowd shouted requests for Church’s “Talladega” as he and Wallen spent several minutes attempting to tune their guitars.

“I’m going home after this one,” Church quipped, the time well past midnight.

“I’m not,” Wallen shot back.

“I’m not playing ‘Talladega,'” Church told fans.

“We really can’t hear anything up here,” Wallen explained. “If it sounds like we don’t know what we’re doing, we don’t.”

Then he took off his guitar and told Church he would let him play the song alone.

“I’ll sing,” Wallen promised.

“Just hang on, hang on,” Church said, frustrated as he wrestled with the tuning pegs on his guitar. “These … things are in the key of Z.”

“Does anyone have anything to drink on them?” Wallen asked.

Someone passed him a shot, and Church told him to gulp it down.

Morgan Wallen and Eric Church.Courtesy Cindy Watts

Morgan Wallen and Eric Church

“Don’t you leave,” Church chided Wallen. “You stay right here.”

Stating his tuning was “close enough,” Church strummed the opening of “Springsteen,” and the crowd cheered.

He forgot the second verse to the song, and Wallen jumped in and helped him out.

“Come on, let’s get … out of here,” Church told Wallen when he hit the last chord and quickly pulled off his guitar.

Wallen waved to the crowd and said: “Thank you guys so much.”

In July, he toldGood Morning America’sMichael Strahanthat he checked into a rehabilitation center after the incident and has since eased back into his public life. In July, hemade a surprise appearanceatLuke Bryan’s Bridgestone Arena concert. In August, he released “Sand in My Boots” to country radio. And earlier this month, Wallen held a benefit concert that raised $725,000 forThe Community Foundation of Middle Tennesseeand theTennessee Emergency Response Fundto assist victims of the recentsevere storms and floodingin Humphreys County and other parts of Middle Tennessee.

source: people.com