The biggest battle at the Proms this summer isn’t the one between the arena and the gallery, Elgar against Vaughan Williams or even the Proms-bashing government minister Margaret Hodge versus the rest of the world. No, it’s deciding which BBC orchestra will get the honour of playing the music to Doctor Who. Believe it or not, it’s easier to get a ticket for Simon Rattle than it is for Murray Gold’s own arrangement of his music to the show on Sunday. The waiting list for tickets, he tells me, has now reached some 3,000.

No wonder that a cold war broke out between the BBC Philharmonic (Manchester) and the BBC National Orchestra of Wales (Cardiff) over who got first dibs. The difficulty being that the BBC Phil traditionally perform the children’s Prom, while BBC NOW have been playing and recording Gold’s exuberant soundtrack for three years.

Perhaps Cardiff has taken enough glory, but it’s in a Manchester studio that I hear a quizzical BBC Phil being put through their paces on pieces such as The Doctor Forever and Martha vs the Master. Gold is apologetic: full brass and percussion notwithstanding, we are still missing the rock band, the choir and a soprano soloist, he whispers to me over the seraphic din. If I reveal any more about the surprises in store for the audience I am fairly certain that BBC heavies will come for me in the night.

The music for Doctor Who has travelled a long way since its origins. But at the centre of this family concert is another key anniversary to add to the alchemy of this year’s Proms: it is 50 years since BBC bosses allowed a rather large cupboard in the corporation’s Maida Vale studios to be given over to the embryonic BBC Radiophonic Workshop. Five years later came Delia Derbyshire’s extraordinary revamp of Ron Grainer’s theme tune to Doctor Who.

The force of what she and her colleage created still resonates. “I didn’t want to touch the theme,” Gold says. “There’s so many things about it that sounded great, and still sound great. It was arrived at organically, so it’s sort beyond fashion. Synthesizer design is always caught in fashion, but Delia’s stuff was made with tape and free-standing oscillators, the component parts of what synthesizers are but arranged in a room. It’s an overused word, but it’s timeless.”

Derbyshire’s profoundly modernist techniques, recently brought to the fore again with the unearthing of her personal archive, are also a reminder that if her invention did inspire the current gurus of dance music such as the Chemical Brothers and Portishead, there’s just as much reason to align her with the classical avant-garde. “You have to look at it within the context of its time,” says Mark Ayres, the archivist of the now defunct workshop and a sound designer for Doctor Who in the 1980s. “Music was pulling in different directions. Serious musicians were using electronics to get away from the equal-tempered scale and tonality, while pop musicians wanted to make something very tonal but used electronics to create new rhythms.”

Arguably when those rhythms became achievable at the touch of a button visionaries such as Derbyshire lost interest. “She was frustrated with the way electronica was going,” Ayres says. “Synthesizers became like scientific instruments. And then you put a keyboard on them and you were back to playing tunes. She wanted to create soundscapes.”

Gold admits that he, too, wanted an edgier, “futuristic” sound when he started working with the new series. But, inspired by the emotional arc of Russell T. Davies’s vision, what emerged was actually a symphonic sound to complement the newly empathetic figure of the Doctor. In fact, it’s hard to imagine David Tennant’s Christlike hero being half as charismatic without those soaring tunes.

Torchbearers of avant-garde electronica may have to pick a different concert to satisfy their fix (I’d suggest the Stock-hausen Day on August 2). As for the classical purists, well, perhaps there’s a pleasing irony here, for what began in Maida Vale as a reaction against an overly familiar sound (the orchestra) is now bringing a new generation to that very same sound, very probably for the first time. As Gold says, “You’d have to be pretty mean-spirited to say that it didn’t serve a purpose.”

The Doctor Who Prom is on Sunday at the Albert Hall and broadcast live on Radio 3 (11am). www.bbc.co.uk/proms

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