A planet full of song sounds like something from a myth or a fairytale. And yet for millions of years Earth was such a place. Forest and grassland across continents was full of birdsong. At sea, great whales sang theme and variations through thousands of miles of the abyss. Man drastically diminished the realm of the birds – first with fire, axe and plough, later with guns, urban development and supercharged agriculture. Britain today has 90% fewer nightingales than it did just 40 years ago. In the ocean, over a period of a few hundred years, Europeans and Americans slaughtered sperm whales, right whales, blue whales and other species in the hundreds of thousands so that by the 1960s more than 99% of most populations had been lost. The sound and fury of engines replaced the old music of the oceans, with whales in small numbers at the margins, or in greatly shrunken sound worlds.