Little Big Town was performing at the historic venue as part of their 2017 residency "Little Big Town at the Mother Church." The Grammy-winning quartet, which consists of Karen Fairchild, Kimberly Schlapman, Phillip Sweet and Jimmy Westbrook, brought Lambert on stage to take lead vocals on a cover of the Dixie Chicks’ “Goodbye Earl" (watch above).
Fairchild had previously promised that they would feature special guests during their six-show residency in a press conference; other guests so far have been Brothers Osborne and Maren Morris. Morris sang an a cappella rendition of “Down By the River to Pray,” a song popularized by the George Clooney movie "O Brother, Where Art Thou?," according to Rolling Stone Country.
Little Big Town's Ryman residency will continue on Sept. 15-16. The group is currently touring North America and will be touring the United Kingdom this fall. Tickets for select performances are available on AXS. Lambert is still on the road with her Highway Vagabond Tour; tickets to select performances are available on AXS.