There was a comment beneath one of these videos which said "I love how Youtube is the closest thing to a time machine we have." And that is very true where music is concerned. The world's entire musical catalogue is more or less available 'on demand' even the most obscure folk tunes from faraway places as well as various transcriptions of what are allegedly the first known tunes from Ancient Greece or Egypt.
It is also a reminder of music we may have known and subsequently forgotten and that is understandable with the huge amount of music we have heard and enjoyed over the years.
And so it was that one of YT's recommendations reminded me of the sisters Ann Wilson and Nancy Wilson (the latter not to be confused with the jazz singer of the same name) who were part of a band called Heart, formed in 1970.
The YT recommendation which alerted me was the final video here, a splendid version of Stairway to Heaven performed for the three surviving members of Led Zeppelin in 2012 :