Music fans around the world shouted, "Welcome back, my friends!" when prog rock pioneers Emerson, Lake & Palmer took the stage together (the first time in 12 years) at London's High Voltage Rock Festival. This video chronicle of ELP's 40th anniversary performance includes such songs as "Karn Evil 9: 1st Impression," "From the Beginning," "Lucky Man," "The Sage," "The Hut of Baba Yaga," and many more. 3 1/2 hrs. Standard; Soundtrack: English Dolby Digital 5.1; interviews.