Elvis Presley, the undisputed king of rock, performs in a concert recorded on December 3, 1968. Airing as an NBC special, this spectacular performance--his first T.V. performance in eight years--has become legendary. Performing alone as well as in special jam sessions with Scotty Moore and D.J. Fontana, his early backing musicians, Elvis puts on the kind of crackling, charismatic show which helped.