Pope Francis and an admiring throng of thousands enjoyed music from the Queen of Soul, Andrea Bocelli and others at the end of his first day in Philadelphia on his first US tour.

Aretha Franklin led an all-star line up at the Festival of Families, one of the events organised by the Vatican-sponsored World Meeting of Families, which brought Pope Francis to the city after visits in Washington DC and New York.

The festival included song, prayer and testimonials from people from different continents on the joys and challenges of family life, including an Argentine couple celebrating their 60th wedding anniversary.

After each family spoke, the Pope greeted and spoke with them, and later addressed the crowd at length about the importance of families, urging people to take special care of children and grandparents.

"In the family, there are difficulties, but those difficulties are overcome with love," he said through an interpreter. "Love is about celebration, love is joy, love is moving forward."

Folk singer Marie Miller, American rock band The Fray and Columbian pop star Juanes also performed at an event hosted by actor Mark Wahlberg.

Wahlberg credited his Catholic faith and a parish priest for turning him around after a rough upbringing in Boston that included cocaine addiction and a series of racially-motivated attacks as a teenager.

"I attribute all of my success to my Catholic faith," he told the crowd. "My faith has given me the ability to be a good father, a good husband and most importantly a good person."

Franklin, 73, best known for her hit Respect, performed Amazing Grace. She had said earlier she planned to present Francis with a gift: a box set of sermons by her father, civil rights activist and preacher CL Franklin.

She later came out and performed Nessun Dorma from the opera Turandot, which she intended as a surprise, but the Pope had left by the time of her encore.

Bocelli, whose rendition of The Lord's Prayer was accompanied by The Philadelphia Orchestra and the Philadelphia Heritage Chorale, has described Francis as "a blessing given to the world".

"This journey represents for the United States a precious opportunity to embrace this giant, a man of God, a gift from heaven, a point of reference and a providential source of hope for our world," he said.

Bocelli also performed another piece after the pontiff left.

Before Pope Francis' arrival, Sister Sledge performed a special rendition of the hit We Are Family, adding another gender to proclaim, "I've got all my sisters and my brothers with me," and referring to Jesus as "the way, the truth, the light".

Comedian Jim Gaffigan also entertained the crowd before the pope's arrival. The 49-year-old Gaffigan attends Mass weekly with his wife and five children and regularly references his Catholicism in his stand-up and on his TV Land sitcom.

Towards the end of the festival, Juanes joined the Pennsylvania Girlchoir and the Keystone State Boychoir in singing both in English and Spanish: "This world needs more love. This world needs more love. This world just needs more love."

Pope Francis greets huge crowds in Philadelphia. Video: Reuters

Sign up to our free newsletters

Get the best updates straight to your inbox:
Please select at least one mailing list.

You can unsubscribe at any time by clicking the link in the footer of our emails. We use Mailchimp as our marketing platform. By subscribing, you acknowledge that your information will be transferred to Mailchimp for processing.