Delia Derbyshire (5 May 1937-3 July 2001) was a British composer who oversaw the BBC Radiophonic Workshop beginning in the 1960s. She was considered a visionary in her use of sound and voice and her early works are considered pioneering efforts in what is now known as electronica (groups from this genre such as Orbital and Portishead have acknowledged her influence).
Her best-known single work was her arrangements of the Doctor Who theme by Ron Grainer. While Grainer composed the basic melody, it is Derbyshire who provided the iconic sounds and form of the theme. Grainer attempted to secure co-writing credit for Derbyshire, but due to rules in place at the time she was not allowed to receive a songwriting credit (although she and the Workshop would be regularly credited on the series).
Derbyshire created three theme arrangements. The first was used only for the pilot version of An Unearthly Child and was more or less identical to the version that was used in the televised version, except for additional sound effects such as a thunderclap. The second version was the televised version used from An Unearthly Child to The Moonbase. When a new title sequence was introduced beginning with The Macra Terror, Derbyshire revised the arrangement of her theme and, with some minor refinements over the years, this version was used through to The Horns of Nimon (it was also to be used for the last time in the story that followed Horns of Nimon, Shada, but that story was never completed or televised). In 1980, Derbyshire's arrangement was retired and replaced by a new one by Peter Howell. Elements of Derbyshire's arrangement have reemerged in the arrangements introduced by Murray Gold in 2005 and late 2007.
Derbyshire is also credited with creating the TARDIS dematerialisation sound effect.
In 2008, the BBC announced the discovery of two hundred sixty-seven tapes of experimental and demo recordings made by Derbyshire in the 1960s and 70s, the existence of which were not known until after her death. Among the recordings found were Doctor Who-like special effects, as well as an experimental electronic music track that has been noted for its astonishing similarity to the electronic dance music of later decades.