Music surrounds us–and we wouldn’t have it any other way. An exhilarating orchestral crescendo can bring tears to our eyes and send shivers down our spines. Background swells add emotive punch to movies and TV shows. Organists at ballgames bring us together, cheering, to our feet. Parents croon soothingly to infants.
And our fondness has deep roots: we have been making music since the dawn of culture. More than 30,000 years ago early humans were already playing bone flutes, percussive instruments and jaw harps–and all known societies throughout the world have had music. Indeed, our appreciation appears to be innate. Infants as young as two months will turn toward consonant, or pleasant, sounds and away from dissonant ones [see box on page 42]. And the same kinds of pleasure centers light up in a person’s brain whether he or she is getting chills listening to a symphony’s denouement or eating chocolate or having sex or taking cocaine.
Therein lies an intriguing biological mystery: Why is music–universally beloved and uniquely powerful in its ability to wring emotions–so pervasive and important to us? Could its emergence have enhanced human survival somehow, such as by aiding courtship, as Geoffrey F. Miller of the University of New Mexico has proposed? Or, as suggested by Robin I. M. Dunbar of the University of Liverpool in England, did it originally help us by promoting social cohesion in groups that had grown too large for grooming? On the other hand, to use the words of Harvard University’s Steven Pinker, is music just auditory cheesecake–a happy accident of evolution that happens to tickle the brain’s fancy?
Neuroscientists don’t yet have the ultimate answers. But in recent years we have begun to gain a firmer understanding of where and how music is processed in the brain, which should lay a foundation for answering evolutionary questions. Collectively, studies of patients with brain injuries and imaging of healthy individuals have unexpectedly uncovered no specialized brain center for music. Rather music engages many areas distributed throughout the brain, including those that are usually involved in other kinds of cognition. The active areas vary with the person’s individual experiences and musical training. The ear has the fewest sensory cells of any sensory organ–3,500 inner hair cells occupy the ear versus 100 million photoreceptors in the eye. Yet our mental response to music is remarkably adaptable; even a little study can retune the way the brain handles musical inputs.