By now, everyone has probably seen the larger-than-life mural of OutKast (André 3000, left, and Big Boi), painted by JEKS, that adorns the wall of WISH ATL, the boutique in Little Five Points. You’ve probably even had your picture taken in front of it if you are a self-respecting Atlanta creative — or aspire to be one.

OutKast makes the music, but they — and other Grammy Award winners who...