I heard a programme on BBC Radio 4 one morning this week about the way immigrants from the Carribean brought Jazz to the UK and mainland Europe in the 1940s. It must have been part of the series. Very interesting programme (to me, not a lover of jazz but interested in history and social/cultural matters). You can find the hidden history series programmes on line: https://www.bbc.co.uk/programmes/m0003r3c