Leon Theremin was born at the end of the 19th Century, died at the end of the 20th. Best known for the electronic instrument that bears his name, although his research helped protect the Kremlin and as an agent of the 'organs' (as the intelligence agency in the USSR was known) he created extraordinary security and listening devices. In the USA he became a musical celebrity, mixing with the cream of the musical elite and that of society. He was also arrested and disappeared into Stalin's labour camps.