Slide-guitar wizard Roy Rogers has racked up a great history of Jazz Fest performances over the years and should add to that list in his set at this year’s event.

“I have a great time down there,” says Rogers. “It’s always been a good time. I’m bringing a special guest, Carlos Reyes. He plays violin and he plays Paraguayan stringed harp. Carlos brings a different sound to it; he and I may do so...