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

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 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 to 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."