Wednesday, April 14, 2010
How Does Music Affect Your Brain?
“Organised sound” might strike you as a pretty neat definition of music. But the phrase was coined by the French-born avant-garde composer Edgar Varèse, who wrote music in the early 20th century that many of his contemporaries would not have accepted as “music” at all. And Varèse wasn’t seeking a catchy general definition that could be applied to anything from Monteverdi to Lead Belly; rather, he used the description to distinguish his bold sonic explorations from conventional music. His compositions called for howling sirens, the ghostly electronic wail of the theremin, and electronically taped ambient noises: rumbling, scraping, jangling, honking and the churning of machines. He gave these works pseudoscientific names: Intégrales, Ionisation, Density 21.5. “I decided,” he said, “to call my music ‘organised sound’ and myself, not a musician, but a ‘worker in rhythms, frequencies and intensities’.” If that was meant to apply to Mozart too, it would make him something like a cross between a laboratory technician and an industrial labourer.
I suspect many people feel disheartened, even appalled, when music is seemingly reduced to a matter of mere acoustics, of the physics and biology of sound and audition. But the mathematics, physics and physiology of acoustic science is not merely an unavoidable introduction to the raw materials of music. It is much more interesting than that.
The building blocks of most music are notes: pitches with particular acoustic frequencies. Each of these is manipulated or sequenced to create melody, harmony, timbre and rhythm. With these ingredients, musicians compile “global” structures: songs and symphonies, jingles and operas, compositions that typically belong to a certain form, style and genre.
note a musical sound (tone) of definite frequency or pitch
pitch the auditory property of a note (key) that is conditioned by its frequency
frequency the number of times that a note or vibration repeats itself in a specified time. Frequency defines whether notes have melody or harmony
melody a group of notes forming a distinctive sequence or structure, ie, a tune
harmony any combination of notes sounded simultaneously, eg, chords
timbre the distinguishing quality of a sound
rhythm the arrangement of the relative durations and stresses of the notes of a melody
We Go Together
When it comes to our vocal cords at least, it seems that men and women are in perfect harmony
We can hear frequencies down to 20Hz (20 vibrations per second), below which we feel rather than hear them. These are called infrasound and are produced by natural processes such as surf, earthquakes and storms. The upper frequency limit of human hearing is typically about 20,000Hz. Higher frequencies than this (ultrasound) are inaudible to humans, but are detected by many other animals.
The human male speaking voice has a typical frequency of around 110Hz, and the female voice an octave higher, 220Hz; so when men and women sing together “in unison”, they are actually singing in octave harmony.
Mind Blowing Decisions
Music is so engaging that the whole human brain wants to join in
Technologies such as magnetic resonance imaging (MRI) are enabling neuroscientists to see exactly what the brain is up to when it processes music and to investigate whether there is any overlap with other mental functions.
As far as music is concerned, MRI studies are something of a mixed blessing. For whereas many cognitive tasks, such as vision or language, have fairly well-localised centres of brain activation, music does not. To put it crudely, when we listen to music, all the lights are apt to come on at once. Pretty much the whole brain may become active: motor centres that govern movement, the “primal” emotion centres, the language modules that seem to process syntax and semantics, the auditory highways…
Unlike language, say, music has no dedicated mental circuitry localised in one or a few particular areas: it is a “whole brain” phenomenon. On the one hand this makes it very challenging to understand what is going on. On the other, it shows why music is so fundamentally important: no other stimulus comparably engages all the cogs of our mental apparatus, and compels them to speak with one another: left to right hemisphere, logic to emotion. It is quite simply a gymnasium for the mind.