The Guardian has a bio and slideshow on Daphne Oram:

She went on to join the BBC, and, while many of the corporation's male staff were away fighting in the second world war, she became a balancing engineer, mixing the sounds captured by microphones at classical music concerts. In those days, nearly all programmes went out live because recording was extremely cumbersome and expensive. Tape hadn't been invented, and cheap computers were half a century away.

Yet when tape did come along, in the early 1950s, Oram was quick to realise that it could be used not simply for recording existing sounds, but for composing a new kind of music. Not the music of instruments, notes and tunes, but the music of ordinary, everyday sound.

After Oram had finished her day's work, and everyone had gone home, she trundled tape recorders the size of industrial gas cookers from empty studios, and gathered them to experiment late into the night. She recorded sounds on to tape, and then cut, spliced and looped them; slowed them down, sped them up, played them backwards. It must have been like working in a laboratory, or inventing new colours – a new world almost impossible to imagine now.

See the Boing-Boing post I cribbed this link from for additional links, including some audio samples. And there's this earlier post about Delia Derbyshire, Oram's colleague at the BBC Radiophonic Workshop.

[via boing-boing]