Book reveals how the jazz musician unwittingly became party to secret cold war manoeuvres by the US in Africa

It was a memorable evening: Louis Armstrong, his wife and a diplomat from the US embassy were out for dinner in a restaurant in what was still Léopoldville, capital of the newly independent Congo.

The trumpeter, singer and band leader, nicknamed Satchmo as a child, was in the middle of a tour of Africa that would stretch over months, organised and sponsored by the State Department in a bid to improve the image of the US in dozens of countries which had just won freedom from colonial regimes.