My dear wife has just unearthed this gem from 1979.
https://www.youtube.com/watch?v=oja7gy7NK74The guest in that programme, Robert Mayer, was the sponsor of the children's concerts I used to go to with my dad. I remember him appearing at the festival hall some time around his 90th birthday. It was much later that I learned that he had once sat next to Brahms in a concert.
David Attenborough looked very young in that, and he is the only survivor from that episode.