Singer Joni Sledge, of disco group Sister Sledge, has hailed their classic hit We Are Family as "a perfect fit" for Pope Francis.
The 59-year-old and her siblings will perform at Philadelphia's Festival of Families event for His Holiness in a star-studded line-up that includes Aretha Franklin and Andrea Bocelli, with actor Mark Wahlberg as host.
During the outdoor festival, scheduled for today, the next-to-last night of the pope's US tour, Sister Sledge will perform their signature hit We Are Family.
"Performing to His Holiness is a whole different level for us, something that we do not take lightly," Sledge said.
"We are absolutely honoured to be asked to do this and we do think our song We Are Family is very sincere; it is a song that we embrace as truth. We think it a perfect fit for His Holiness Pope Francis."
Composed by Chic's Nile Rodgers and Bernard Edwards, We Are Family was a top 10 hit for Sister Sledge in the UK, reaching number two on the Billboard Chart in the US. It quickly became a disco anthem and has since grown to over 1 billion digital downloads.
The American insisted performing We Are Family for over 35 years has been a privilege: "When we sing it, we get so much love from the audience that it inspires us to keep going," she said.
A global hit, the song has followed the sisters all over the world. "I remember being on safari once in South Africa and all these people on the top of this hill were pointing frantically and I thought maybe there was an elephant or something.
"I was like, 'what'? and I got scared. I ran straight down the hill and they started embracing me and saying "Family!" That was such a huge compliment. I'm like, 'what did I do to deserve this'?"
The singer also revealed that they will perform a special version of the song. "A few of the words are changed, but the biggest difference is the arrangement and spectacular band," she enthused.
"We are very excited, we are also bringing some of our own children up on stage, some of our own daughters. It's going to be historic for their generation, and their children's children. I just can't get over the fact that We Are Family has been so timeless for us."
Formed in Philadelphia in 1971, Sister Sledge originally comprised Joni alongside her sisters Debbie, Kathy and Kim. Kathy left in 1989, but occasionally joins her sisters for selected performances and releases.
However, there are no feelings of bitterness. "The most important thing is respect. I think respect is what has lived in the group to keep us together. We have one sister who has gone solo, but that has not waned our respect for her and we completely support her in all her endeavours."
The music industry has changed since Sister Sledge were at their height in the late 1970s and early 1980s, but the family-friendly group have no time for today's explicit music videos featuring scantily-clad women shaking everything.
"Women should respect themselves," the singer insisted. "Our new release that we have coming out in January is called WAMOW. It's an acronym for 'women are the music of the world'.
"We have met so many WAMOWs in our lives all over the world, just beautiful people like Oprah Winfrey and the late Maya Angelou - beautiful women in every walk of life, every culture. We're just delighted to do a song that pays homage to them.
"Every woman has the propensity to be that and hopefully our song will influence them and the choices they make to reflect beauty from the inside out."
When asked if Sister Sledge hope to get the pope dancing, the singer laughed. "I believe that is totally up to His Holiness and we would not approach him that way."
She added: "What we can hope to deliver is his message to the world and the meaning of family. His message is every single human being deserves to be loved and hopefully that is what we can do. If we can do that then we have delivered."