Actor and reformed Catholic Mark Wahlberg served as emcee for the World Meeting of Families in Philadelphia, Pennsylvania, which was held to mark the Pontiff's first visit to the city. Pope Francis and the 300,000-strong audience were treated to performances by artists like The Fray, rocker Juanes, opera star Andrea Bocelli and soul icon Aretha Franklin, but Wahlberg courted controversy as he made a cheeky comment about his work on the R-rated film.