>I rarely understand lyrics these days but any old recording ...

Now you are showing your age. Isn't that a fundamental difference between any music pre-1960 and post-1960.

I did happen to notice that when they did all those "best of the century" lists in 1999/2000, nearly all the songs which got to the top of the UK lists had intelligible lyrics Imagine(John Lennon), Bohemian Rhapsody(Queen), Angels(Robbie Williams) etc, mondegreens notwithstanding.