sixty-seven

For over a decade, leading cellist Beatrice Harrison dueted with nightingales.

In 1922, she had moved to the Surrey countryside, to an isolated house surrounded by woodland. Practising in the garden one afternoon, she was amazed when a bird joined in with her song: it followed her own trills, staying in tune with the cello.

She persuaded Lord Reith, the director of the BBC, to send a crew to her garden to record this duet. It was to be the very first live outdoor broadcast and Reith - despite his objections of cost - could not resist.

A million people listened to this first recording, and Harrison was almost smothered with fan mail; the duet became an annual event, carrying on for twelve years until Harrison moved house. After that, the broadcasts featured the nightingales alone. The pieces are lovely and ethereal, marrying human music and bird song in a strange partnership.

The transmission from 1942, however, is more chilling: the live broadcast was pulled when duty engineer realised he could hear the hum of approaching aircraft - not what the BBC wanted to be broadcasting in wartime.

And that distant burring of engines records the British airforce on their way to raid Mannheim, part of the 'Thousand Bomber' policy that would see German towns - most notably Cologne - devastated.

Some of the recordings, including the one made in 1942, can be heard here.