BBC News has a short piece—with some audio samples—on a cache of 267 audiotapes made in the 1960s and 1970s by Delia Derbyshire, an early BBC Radiophonic Workshop member and electronic audio pioneer who, among other things, created the theme music for Doctor Who (from a score composed by Ron Grainer). The Doctor Who theme is among the more conventional things the Radiophonic Workshop did; these people were seriously ahead of their time. (According to the archivist working with the tapes, Derbyshire "got a bit disheartened and a bit bored with it all when the synthesizer came along and it all became a little too easy.")

The also BBC has a brief page covering Alchemists of Sound, a BBC TV documentary about the Radiophonic Workshop (including some free clips); Sound on Sound ran an extensive piece on the group, although you can only read the first few thousand words before you're asked to pay for a PDF. (Worth the 99 pence if you're interested—I read the piece in print a couple of months ago.)