Western ears consider a pitch at double the frequency of a lower pitch to be the same note, an octave higher. The Tsimane’, an indigenous people in the Bolivian Amazon basin, do not. “If you only test ...

Two simple notes – E and F – have become synonymous with tension, fear and sharks, representing the primal dread of being stalked by a predator. And they largely have “Jaws” to thank. Fifty years ago, ...