I remember being excited to see this in 1973 but I don't remember what the circumstances were. There was no such thing as home video recording then. If you wanted to immortalize something, you put a portable cassette recorder in front of the TV speaker and made a difficult-to-listen-to audio recording that you then listened to until the cassette tape snapped from the strain.
But it was a year or so later that my Aunt Sally got the very first Betamax recorder known to Riverdale, Westchester or Greater Bergen County New Jersey and began recording Merv Griffin, Mike Douglas, and Johnny Carson shows that featured her favorite performers, as well as PBS miniseries.
That said, I am amazed at the quality of this clip.