The Zac Brown Band hosted numerous country and pop artists at the Southern Ground Music and Food Festival at Riverfront Park in downtown Nashville on Friday and Saturday (Sept. 21-22). On the first night, the group brought out Alan Jackson to sing "As She's Walking Away" and "Dixie Highway." Later in the festival, they invited friends like Gregg Allman, Sheryl Crow and Dwight Yoakam to share the stage. The lineup also featured Jerry Douglas, David Gray, Amos Lee and the Lumineers, among many others. The next Southern Ground festival will take place in Charleston, S.C., on Oct. 20-21.