This week I handed the reins once more to my brother Neil Young, for a London edition. Let's ride! Monday I don’t ride today. While degreasing my chain I listen to a radio feature about the bioacoustician Bernie Krause, who’s spent decades recording the sounds of nature. Krause discovered that a natural environment unaffected by species and habitat loss occupies the full frequency spectrum, but as things fall out of joint the orchestra begins to break apart; the range of frequencies becomes gap-toothed. Often the landscape doesn't look different at all – it's the soundscape where the devastating changes are first evident. The insects’ rich thrum drifts away. The frogs fall silent. The hedgehogs no longer rustle.