Query: What is the name of festival held in Spoleto?
Context: Charleston has one official sister city, Spoleto, Umbria, Italy. The relationship between the two cities began when Pulitzer Prize-winning Italian composer Gian Carlo Menotti selected Charleston as the city to host the American version of Spoleto's annual Festival of Two Worlds. "Looking for a city that would provide the charm of Spoleto, as well as its wealth of theaters, churches, and other performance spaces, they selected Charleston, South Carolina, as the ideal location.