BBC 3's "Free Thinking" programme did a rather nice potted history of the BBC Radiophonic Workshop. It's about forty-five minutes and available as a podcast here (download link here). There are rather a lot of Doctor Who in-jokes, as you'd expect (serious discussion about it starts around the fifteen minute mark, if you're impatient).
Here's the programme description: "The BBC Radiophonic workshop, opened in 1958 with an aim to experiment
and produce original music for various iconic BBC programmes. It was
shut down 40 years later by Director General John Birt.
In an edition recorded just as the Workshop prepare to release a new
album, and tour the UK, Matthew Sweet brings together Radiophonic
Workshop members Dick Mills, Paddy Kingsland, Roger Limb, Peter Howells,
and Mark Ayres to reflect on the days and nights they spent in the
workshop, coaxing ageing machines into otherworldly life, and pioneering
electronic music." Also a bit from an archived Delia Derbyshire interview. It's all quite fun.