A conductor is a person who directs the performance of a composer's score. In this pursuit, he or she will be most concerned with determining when individual instruments play their parts of the music. Often, but not always, the conductor will also be the orchestrator of the orchestra.
In Doctor Who history, conductors were only credited on special occasion, as with The End of Time. During the Moffat era, the conductor began to be credited on a more regular basis. As of 2012[update] the only individuals ever credited as a conductor on Doctor Who were Marcus Dods, the only credited conductor on the 1963 version of the show and Jeremy Holland-Smith, Ben Foster and David Temple, though for The Sensorites Norman Kay had the specific credit of "Incidental music composed and conducted by", as did Raymond Jones on The Romans and Carey Blyton on Doctor Who and the Silurians.