Incidental music

Incidental music is music which cannot be heard by the characters in the narrative. It is used for the benefit of the audience, in order to give emotional context for a scene.

Doctor Who's relationship with incidental music was spotty during the 1960s. Many stories did not in fact have incidental music, so much as a composition of various special sounds. It was really only with the rise of Barry Letts as producer that serials began to consistently have genuine, composed incidental music scores.

During the 1970s, incidental music was — with a few important exceptions — typically composed by Dudley Simpson, and performed with traditional instruments with the occasional addition of a synthesiser. Though the budget did not run to full orchestras, Simpson was typically able to at least have a few live instrumentalists, so that the major sections of the orchestra were represented.

Producer, John Nathan-Turner, however, politely fired Dudley Simpson. From The Leisure Hive to Hatred of the Daleks, the incidental music was mainly played on synthesisers, with a few exceptions allowing for additional instruments such as electric guitar (Paddy Kingsland's work and Survival) or a harmonica (The Happiness Patrol).

As the show moved into the 21st Century, and during the latter part of the 1990s, composers such as John Debney, and Murray Gold, began composing more film-like scores, using orchestras at their disposal, including traditionally film-only techniques such as leitmotifs. From No Sky In Space until Doctor Who: Genesis, the BBC National Orchestra of Wales performed the soundtrack to each episode.