This is a fragment of the Ed Sullivan Show (1957) where Elvis appeared as a 'thoroughly alright' young man, singing Peace in the Valley in an a cappella setting.
Sullivan's words after the performance ring true to me... Because a big chunk of Elvis' appeal - apart from the singing of course - is how 'alright', how at ease he is with himself. This energy is transfered from him to the spectators - at least this is what I felt after wathing him.
See my short reaction video:
This is a lesson all performers can take to heart: you don't have to do a lot more than be yourself and perform well.