I just saw the last South Bank Show. It has been presented on television in Britain since 1970 by Melvyn Bragg (he did the script for Ken's films The Debussy Film in 65, The Music Lovers and many more up to Classic Widows in 1995). The show has premiered lots of stuff by Ken.
It was broadcast by LWT Television on the south bank of the Thames (which gave the programme its name) and covered arts just as Huw Weldon's Monitor programmes did. Memorable programmes for me were the interview with dramatist Dennis Potter, dying of cancer and having to take morphine during the interview, and the one on composer Peter Maxwell Davis (who coincidentally did the music for The Devils and The Boyfriend).
Sad that the show ends. It was also one of the few outlets for Ken's work.