I was playing a recording of some of my microtonal music to a friend. Suddenly a very peculiar expression came upon his face. He then placed a finger into one of his ears. I didn't know how to interpret this. If he had placed both fingers into both ears I would have understood and turned down the music or turned it off completely. Well, it turns out he was deaf in the other ear, but to his surprise, he could actually hear this song with his bad ear. This was the first time he could hear anything with that ear for many years. He plugged his good ear to analyze better the hearing in his bad ear. He reported that he could hear portions of the song pretty clearly.
Why is this? Of course I don't know for sure. I'm not a doctor. But I have some ideas based on my study of music. The piece being played was written in thirteen note equal temperament. The vast majority of music we hear today is written in twelve tone tone equal temperament, a tuning that is considered to be fairly harmonious or consonant. Thirteen note tuning is, on the other hand, extremely dissonant. Some people consider it to be one of the worst possible tunings and, based on conventional harmonic theory, it is simply awful. I disagree with this assessment, but I would rather discuss, for now, possible reasons for this specific tuning's peculiar effect on this individual.
Most tones from an instrument are actually made up multiple overtones all playing at the same time. This is one reason why different instruments often sound so different even when they are playing the same note. The fundamental notes may be the same but the overtones are different or have different intensities.
Things get interesting when tones are combined. They interact in complicated ways. New combination tones are created and the new waveforms that result can be very complex.
The amount of complexity that results from tones interacting with each other can be reduced if the frequencies of the tones are simple ratios of each other. We consider these tones to be harmonious, whereas tones that interact in a more complicated way are considered dissonant.
Now I should point out something obvious. Since dissonant interactions are more complicated, they are harder to understand and, therefore, less well understood. Dissonance has also been a neglected subject. Harmony has been the subject and goal of most music theory. Harmony is a far easier subject to study and is often considered to be a lofty goal in itself. Harmony is tied up up with all sorts of romantic notions of what is pure and beautiful about the universe.
Dissonance, however, is vilified, often with no real understanding of what dissonance really is.
What's remarkable is that our modern tuning system of twelve equally spaced semitones in an octave ever caught on. Early on it faced passionate opposition because it deviated from so called pure and natural intervals. But it does have technical advantages and was eventually adopted, largely as a matter of convenience.
This is a strange irony. Our romantic notions of harmony really haven't changed much since ancient times, but most people view our modern tuning system with its introduced dissonances as a manifestion of perfect harmony, a realization of their romantic ideals. Of course this irony goes largely unrecognised because most people don't realise the true nature of our modern tuning system.
Of course some people are fully aware of this contradiction. The elimination or reduction of the dissonances in modern twelve tone tuning is a major force behind the modern microtonal movement. But it turns out that dissonance is harder to eliminate than it might seem. Different scales often just introduce different dissonances. (I'll save that story for another day) Others consider our modern tuning to be the best possible compromise. They may lament the impure intervals but consider them to be necessary imperfections.
Do we have to be content with this state of affairs? Is dissonance just a necessary imperfection, an unavoidable wart of nature? This is too big of a question to answer today, but if we return to the beginning we can at least give ourselves some food for thought. I believe one of the reasons my friend could hear that song in a strange tuning is because of the peculiar dissonances of that tuning. Somehow, it appears that the complex vibrations of that tuning interacted with his damaged ear in a complex way and caused it to send messages to his brain.
I have said almost nothing about the possible beauty or musical uses of dissonance, but I hope that I have at least demonstrated some of the power and mystery of it.
I know I have raised more questions than answers, but don't despair, this blog is new and there's a lot more coming. Stay tuned!