You may have read recently of how old recordings of Delia Derbyshire have been found, and how one track sounds very much like something that could have come out last week. You can read the article and hear samples here (it's also worth reading the comments in this post for more info). Delia created the Doctor Who theme while working in the BBC Workshop, which was set up by Daphne Oram, and there is an article about her, her work and some samples of her work here.
There are some great videos on Youtube about Delia and of her work, here are some of them:
Delia Derbyshire - Love Without Sound (1969)
Reel-to-Reel Beat Matching Virtuosa
There is also a great series by BBC4 about their Workshop:
The Alchemists of Sound (Part 1)
The Alchemists of Sound (Part 2)
The Alchemists of Sound (Part 3)
The Alchemists of Sound (Part 4)
The Alchemists of Sound (Part 5)
The Alchemists of Sound (Part 6)
And here is the oldest known 'Computer Music', from 1951.