Combs keyed up expectations as he told fans something special was on the way to help him close out an already-rousing festival set. Playing somewhat coy, he sang the first portion of "Friends in Low Places," only for Brooks to quietly appear on stage and take over.

The musician took his own turn popping up during another artist's performance when he joined Backstreet Boys for "I Want It That Way" later that night

Luke Combs threw a whole lot of exciting curveballs during his headlining Stagecoach set on Sunday (April 27), and one of them was an appearance from pop-punk rockers Good Charlotte. The band's Benji and Joel Madden hopped onstage with Combs to perform "The Anthem," a 2003 mega-hit off their first studio album.