Fans who turned out for the second concert of Miranda Lambert's two-show residency at the Country Music Hall of Fame's CMA Theater on Wednesday evening (Sept. 26) were in for a surprise: The country superstar showed up to play a full set with her trio, the Pistol Annies.

While Lambert had previously brought her trio-mates Angaleena Presley and Ashley Monroe out for special surprise appearances during her solo tour stops, it was the group's first full performance since they last put out new music five years ago, in 2013. More importantly, it signaled the impeding arrival of a new album.

The Annies performed a wide selection of hits from their first two albums during their extended set at the Hall of Fame. For months, the group has been teasing that new music was in the works, so fans were on the edge of their seats waiting for new music during the show. The trio didn't disappoint: Towards the end of their performance, they played three brand-new songs off their forthcoming album, "Best Years of My Life," "Interstate Gospel" (which is also the title of the new project) and "Got My Name Changed Back."

On Thursday, (Sept. 27), the Pistol Annies officially announced their third studio album, Interstate Gospel, as well as three shows in support of the new music. For now, though, here are a few things fans in attendance at the Country Music Hall of Fame learned about the new project and the trio.

See More Photos From the Pistol Annies' HoF Show!