This is the remarkable story of Elizabeth Poston, who was best known for her film scores and popular songs, but who led a secret life of musical espionage. Poston devised musical codes in order to send messages all over Europe.

Using newly declassified documents, we will reveal how these codes were brilliantly constructed, as well as the latest research into what they meant.

MUSIC & FACTUAL

Broadcast on Radio 4 in May 2006