One of the most iconic elements of long-running science fiction series Doctor Who is the distinctive theme music that, despite mutations to accompany the incarnation of each new Doctor, essentially remains true to the original composition from 1963.

This is the creation of Delia Derbyshire, an electronic music pioneer, who worked with the BBC Radiophonic Workshop (they also created the satisfyingly thrilling "whargh" sound the Tardis makes upon appearing).

The most impressive thing about her work is that each single note was created manually, manipulated through oscillators with the final track spliced together using razor blades to tape. This BBC Radio 4 documentary on the life of Derbyshire is essential listening for anyone interested in the history of electronic music. iti.ms/1rNCAts