We know that Juanes’ good looks and smooth voice holds a special power over throngs of fans worldwide, but it wasn’t until last month that we learned that he can actually stop bullets. When Juanes returned to his hometown of Medellín to join local musical and civil society groups in a concert on International Peace Day in one of the city’s poorest neighborhoods, Comuna Trece, they convinced hundreds of members of the city’s violent gangs to commit themselves to peace.