Evanescence, David Gray, Angelique Kidjo, Janelle Monáe, Jill Scott, Sugarland and the World Youth Choir perform at a concert honoring 2011 Nobel peace laureates Tawakkol Karman, Ellen Johnson Sirleaf and Leymah Gbowee. Hosts: Helen Mirren; Rosario Dawson. From Norway's Oslo Spektrum Arena.