In May 1942 in the early days of live outside broadcast, the BBC were recording the song of a nightingale. As they started their broadcast a distant rumble increased in volume as 197 Wellinton and Lancaster bombers appeared overhead on their way to Mannheim for a massive air raid. The contrast of the innocent song and the secret mission gives the recording an emotional resonance.
I remember being woken in the night to listen to nightingales in the woods when I was little. Weird.