This week's castaway on Desert Island Discs grew up in a conventional white South African family. Shielded from the true history of her country under apartheid, she played in the shadow of a Pretoria prison where many hundreds of black men and women were hanged, and never questioned what went on there. Then Mary Benson read the book Cry the Beloved Country. From that moment on, she became a ceaseless campaigner for the rights of black South Africans and dedicated her life to documenting their struggle. This week she talks to Sue Lawley about her search for a purpose to her life and chooses the music which has meant most to her.

[Taken from the original programme material for this archive edition of Desert Island Discs]

Favourite track: Eroica Variations Opus 35 Fourth Bagatelles, Opus 126 by Ludwig van Beethoven