Robert Jourdain offered these amazing explanations of music (a while ago) in a book titled Music, the Brain and Ecstasy. Fascinating to read (and fascinating metaphors, too)…
“Almost all of our auditory experience is devoted to identifying things: a faucet dripping, a spoken word, a clarinet’s warble. We’re far more interested in what sounds are than in where they are. Minds like ours map the world so effectively that the locations of sounds are of little concern. We already know perfectly well where the faucet is. It’s usually only in settings like busy streets and dark alleys that we become conscious of a sound’s location and may evens train to fix its position accurately.
Localization is also important in our experience of music. In a concert hall, reverberations reach our ears from all directions, and we localize each. sounds arriving directly from the stage normally are loudest, so we tend to experience music as coming from that spot. But myriad echoes, some pronounced, most too subtle to distinguish, turn what would be a wallop of sound into an embrace. By surrounding us, music is transformed into an environment we inhabit, a world we are at the mercy of. Take a performance outside so there are no walls to return reverberations, and music is reduced to one presence of many in the world rather than a world in itself.” (p.20)
“Cutting Up Pitch Space
We call a system of tonal categorization a scale. Like the scale found at the bottom of a wall map, a musical scale provides units of measure, but for pitch space rather than geographical space. The basic unit is called a half-step (or a semitone). Every key along a piano keyboard represents a half-step. From C to C-sharp is a half-step, and so is from E to F. In the scale system we’re accustomed to in the West, there are twelve half-steps (and twelve piano keys) in any octave, say, from middle C to the C above.
The precise frequencies used for scale tones are unimportant. If a violinist retunes middle A from 440 cycles per second to 450, your brain will adjust its categorizations accordingly. And so it is the relative distances between frequencies that the brain categorizes. Every time you sing “Happy Birthday to You,” you’ll probably begin on a different pitch. This means that you don’t require the rare skill of absolute pitch (the ability to identify precise frequencies) in order to comprehend music. Research has shown that we’re so oblivious to precise pitch that we take no notice when the tuning of a piece is very slowly raised or lowered as it is performed.” (p.66)
“In principle, we can categorize pitch space any way we like. Instead of eighty-eight keys along a piano keyboard, the same span of frequencies might be divided into eighty notes, or one hundred. But there are good reasons for having exactly eighty-eight notes. The divisions of pitch space are far from arbitrary. Some aspects of the scales we use are clearly determined by the way our brains interpret sound. Other aspects also suggest a biological basis, but not of such potency that they cannot be overridden by training. And further aspects are merely a matter of historical happenstance. Hence the world’s many cultures categorize pitch space in very different ways. The traditional scales of Madras are quite different from the traditional scales of Vienna, and neither have much in common with the scales of New Guinea.” (pp.66-67)
“We have become so accustomed to our scales that any deviations from them sound out of tune or downright dissonant. There’s a certain righteousness in our attitude toward our scales, an arrogance that increases as the Western scale system colonizes much of the non-European world (partly by means of the inherent tunings of musical instruments we export). So its hard to realize that there are other useful ways of cutting up pitch space. When we hear “exotic” music from other cultures, we assume that it is entirely the music’s structure that is “exotic,” not realizing that the tones themselves bear alien relationships.” (p.74)
“The Birth of Harmony
“The harmony of virtually all the music we hear, whether Chopin or Elvis, is rooted in chants sung by medieval Christian monks. The earliest examples of these chants would hardly be regarded as music by today’s standards. They consisted of a single melodic line wavering up and down by a half-step or two, without dramatic leaps, with nearly every note held long, and with no beat but for the natural rhythm of spoken language. Early chant was really nothing more than adorned prayer in which certain vowel sounds were accorded fixed pitch. It was words rather than tones that mattered most to its singers.
In time, vocal range expanded toward high notes and low notes that [-p.94] not all singers could manage. And so chants were separated into two or more vocal lines – parts – that were identical in every way but for being separated by several steps. Parts were usually divided by half an octave to form intervals considered most consonant and “perfect.”
This way of singing prayers, called organum, continued for hundreds of years. But starting in the eleventh century, the individual parts of organum began to go separate ways. They upper part was often made more complex than the others, taking on more embellishments. And lower parts began to follow their own melodic line, sometimes moving in contrary directions to the treble. Paticularly at Notre Dame Cathedral in Paris, a group of church composers wrote music in which voices shifted out of sync and moved independently across time for long stretches, although alternately falling back into unison in the older style.
To medieval ears this new music sounded revolutionary, and rightly so. Chant had become multimelodic – polyphonic – with several independent lines sung simultaneously.” (pp.93-94)
“If good harmony were merely a matter of avoiding dissonance, the composer’s task would be much simplified. Music can be made consonant by keeping to the seven scale tones of the prevailing key and by building only simple chords. Yet music written along these lines is no more harmonious than a blank canvas is balanced. Harmony needs dissonance just like a good story needs suspense.
In storytelling, suspense is created by leading a character from initial safety to increasing peril. A good plot wavers back and forth between relative security and danger, returning to complete repose only at the conclusion. There are moments of extreme tension as bullets fly, but these do not last long, lest the audience become too accustomed and lose its sensitivity. The story’s drama lies not so much in the extremes of great tension and repose as in the experience of passing between them. Like a roller-coaster ride, what matters is not how high you go, but how far you dive.
The same is true in music. A tonal center is established in the listener’s mind and becomes associated with harmonic normalcy. This center becomes the anchor point from which all tones and intervals and chords are measured and compared. It is a constant reference point, a sort of pull of gravity. Adept composers tease the listener with the tonal center, pulling away from it and then promising again and again to return, but always holding back. Only after lengthy expeditions in other harmonic realms, realms that orbit lesser tonal centers, is the listener granted release from his agony. Inferior composers make quick, perfunctory returns to tonal centers, or travel so far from them that the listener hardly recognizes them when finally brought home. The trick is to find just the right balance between reinforcing tonal centers and violating them.” (p.105)
Ref: (italics in original) Robert Jourdain Music, the brain, and ecstasy; how music captures our imagination. Avon Books: New York 1997