Composed by Ron Grainer in 1963, the music was given its eerie, other-worldly electronic arrangement by Delia Derbyshire, a member of the BBC’s Radiophonic Workshop, in a pre-synthesiser era. Every note was created by using a combination of individually struck piano strings, wave signal generators, noise generators, filters and square- and sine-wave oscillators. Recorded onto magnetic tape, each note was cut up and then edited together.

On hearing Derbyshire’s arrangement, Grainer is said to have quipped, "Did I write that?" Thanks to BBC bureaucrats – who wanted all members of the Radiophonic Workshop to be kept strictly anonymous, Derbyshire was denied both a composing credit and a share of the royalties, despite Grainer’s attempts to rectify this.

New versions

The original arrangement has been modified over the years, to reflect changes in the series itself: for instance, during the 1970s, an electronic shriek was added to the theme at the end of episodes, and to signify a "cliffhanger" story. In 1980, Doctor Who’s new producer, John Nathan-Turner, commissioned a new arrangement of the music from the Workshop’s Peter Howell; by now, a new generation of synthesisers were available to beef up the bassline and add more echo.

In 1972, an attempt was made to further modernise the theme tune, using the Radiophonic Workshop's new Delaware synthesiser - but BBC executives didn’t like the harsh tones emitted by the synth, and rejected the new music. However, it is still possible to hear this arrangement, as it was accidentally left on some episodes which were sold to Australia, and is now available as an "extra" on the DVD of Carnival Of Monsters, starring Jon Pertwee.

In 1972, Pertwee recorded a version of the theme, called Who Is The Doctor, speaking lyrics (à la Telly Savalas) to the music. This song was covered in 2004 by novelty band the Nick Atoms. Many other musicians, including Coldcut, Orbital and even The Pogues, have also used the Doctor Who theme as the basis for tracks. In 2005, Franz Ferdinand made their stage entrances to Peter Howell's 1980 arrangement.

The 1996 feature-length Doctor Who, starring Paul McGann, had a fully orchestrated version. When the series returned to television in 2005, Murray Gold was the man tasked with giving the theme a contemporary feel - his arrangement featured samples from the 1963 original, along with orchestral sounds.

The contribution to the development of electronic music made by the uncredited Delia Derbyshire (who died in 2001) has - albeit belatedly - been recognised. In 2002, a BBC Radio 4 play, Blue Veils And Golden Sands, about her work at the Radiophonic Workshop, was broadcast. Two years later, she was also the subject of a play, Standing Wave - Delia Derbyshire in the 60s, written by Nicola McCartney and performed at Glasgow’s Tron Theatre.

• Some of Derbyshire’s best 1960s electronic musical creations during her time the BBC are available on the 2002 CD BBC Radiophonic Music (BBC Records).