The veteran superstar is set to sing for the Pontiff at a special event in Philadelphia, Pennsylvania on Saturday night (26Sep15).

She will also be granted an audience with the head of the Catholic Church, and she is planning to give him a collection of sermons written by her preacher father.

"He (my father) was a theologian and gave very dynamic and educational sermons," Aretha explains to the New York Post. "If he could have met the pope, it would have been a very exciting discussion."

Aretha's dad C.L. Franklin died in 1984. She honed her singing skills as a youngster by performing at his Baptist church in Detroit, Michigan.

The star is planning to sing gospel standard Amazing Grace to Pope Francis, but she is keeping her second song choice a secret: "I want it to be a surprise, but I think Pope Francis will like it."

She goes on to confess her nerves about the big event, saying, "I do have some butterflies. It doesn't happen often!"

Aretha, who previously sang for Pope John Paul II in 1987, says of the latest Catholic leader, "He shows he has personal humility when he talks about himself as the son of an immigrant. He remembers where he comes from, and he has not been overwhelmed by the things he's been given or the huge title of Pope. There's a greatness in humility. I subscribe to that myself in my life. I don't get carried away with the things that people give me, because people don't have to give you anything!"