Free Thinking   Radio 3
Oliver Postgate

The creator of much-loved children's TV classics including The Clangers, Bagpuss and Pogles' Wood is discussed by Matthew Sweet and his guests Daniel Postgate, who took over Smallfilms from his father, singer Sandra Kerr, who was the voice of Madeleine in Bagpuss, composer and author Neil Brand, and writer and broadcaster Samira Ahmed.
Oliver Postgate's father was a communist and his mother was a political activist, daughter of prominent Labour figure George Lansbury - how much of this political background can we find in the fantastical worlds that he created?
There's also discussion of the music that plays such a major role in the programmes - the deep folk roots of the songs performed by Sandra and John Faulkner in Bagpuss and Vernon Elliot's sparse and poignant compositions for The Clangers, Noggin the Nog and Ivor the Engine.    

There's also some discussion of The Critics Group.

;) includes some discussion actually carried out in Clanger ;)

https://www.bbc.co.uk/programmes/m001cyny