It can bring us to tears or to our feet, drive us into battle or lull us to sleep. Music is indeed remarkable in its power over all humankind. Perhaps for that very reason, no human culture on earth has ever lived without it: people making music predates agriculture and perhaps even language. Take, for instance, the recent discoveries in France and Slovenia of surprisingly sophisticated, sweet-sounding flutes, made by our Neandertal cousins. Some of these instruments, carved from animal bones, are as much as 53,000 years old¿more than twice as old as the famed cave paintings in Lascaux.
Despite the ancient and primal nature of music, though, scientists have struggled with some very fundamental questions about its origins and purpose. How does the brain process music? Are there special neural circuits dedicated to creating or interpreting it? If so, are they, like language, unique to human beings? Or do other animals possess true musical ability? Why is an appreciation for music practically universal? Has it conveyed some evolutionary advantage through time? The field of biomusicology is still fairly young, but during the past few years, it has started to answer some of these questions.
Perhaps most basic, researchers have discovered that music¿like language¿stimulates many areas in the brain, including regions normally involved in other kinds of thinking. For this reason, Mark Jude Tramo of the Harvard Medical School argues in a recent issue of Science that the brain doesn't have a specific "music center," as others have suggested. As an example, he points to the left planum temporale. This tiny brain region is critical to the golden musical gift of perfect pitch¿the rare ability to recognize by ear a perfect middle C hit on the piano, or the E of a passing car horn. But the left planum temporale also plays an important role in language processing. Thus, Tramo writes, there is "no grossly identifiable brain structure that works solely during music cognition. However, distinctive patterns of neural activity within the auditory cortex and other areas of the brain may imbue specificity to the processing of music."
Some of the patterns Tramo talks about have revealed themselves through neuroimaging studies¿others through tests on patients that, like the subjects of Oliver Sacks's popular books, have suffered unusual forms of brain damage. In the late 1990s, for instance, Isabelle Peretz at the University of Montreal and Catherine Li¿geois-Chauvel of INSERM in Marseilles ran several experiments on 65 people who, because of epilepsy, had had part of one or the other temporal lobe surgically removed. From these studies they concluded that musicality resided primarily on one side of the brain¿the right hemisphere.
The experiments were simple: Peretz and Li¿geois-Chauvel played different songs for each patient twice. Sometimes the melodies were exactly the same. Other times, they had changed in one of several attributes, which researchers describe as "dimensions": first among them is pitch, which pertains to the actual frequency of a particular tone; the second is rhythm, or the duration of series of notes; the third is tempo, the overall pace of a piece; the fourth is contour, which describes the shape of a melody, or its pattern of rises and falls in notes; the fifth is key, or the set of pitches to which notes in a melody belong; other dimensions include timbre, loudness and spatial location.