I've attached a passage from a piece I'm working on which is about African
bell choirs. You have several musicians, each playing a bell. The bell
may have a single head, or multiple heads. All of the musicians except one
is playing a fixed rhythmic pattern. The various rhythmic patterns
interlock to produce an overall pattern in which one can hear a "melody"
consisting of tones from each of the interlocking lines (it's not like
Western multi-part harmony, where the melody is carred in the top voice and
the other voices provide harmonic support). The individual patterns don't
necessarily have the same period nor phase (though often enough they do).
One musician is the lead player & this player will improvise patterns of
various length & phase which interact with the ground in ways whose
interest depends on the skill of this lead player. Beyond this (I'm
describing a session led by my friend Ade Knowles):
. . . when the music is really rocking, when spirits were high and a cool
sweat begins to form, you begin to hear tones that no one is playing,
high-pitched tones that flitted from place to place like melodic
butterflies. Ade assured me that these tones were simply "the magic of the
bells." That is to say, the magic tones were old friends, who dropped in
whenever, and only when, the music was rocking and the musicians locked
solid into a deep groove. If you play bells with competent musicians,
sooner or later you will become part of the magic. That magic is thus
nothing special. It is open to all.
These magic tones are the sort of thing that tempts one to talk of spirits
invoked by the music. And, that, no doubt, is how some people explain those
tones. They are spirit voices.
However, I am not willing to toss Western science and rationality aside.
Thus I am more inclined to explain those tones through the precisely
physical. My guess, and that is all that it is, is that these tones result
from what physicists call constructive interference. If you have ever
watched the surface of a body of water where various boats are sailing
chances are you have seen constructive interference. When the wakes from
two boats cross one another there will be some patches where the waves
cancel one another out and the water is smooth; that is destructive
interference. There will be other patches where the waves reinforce one
another, making the water even choppier than that in a single wake. Those
patches show constructive interference. In the case of the magic tones from
the bells, each bell is vibrating at many different frequencies, some
louder than others. If the sounds from the bells are very precisely
synchronized, you will get constructive interference between some
frequencies which aren't loud enough in any one bell to be distinctly heard
unless they are reinforced with sound from one or more other bells.
How do people get so precisely synchronized? By locking in to built-in
expressive rhythms that are the same for everyone and that emerge during
emotional excitement and engagement. This synchronization is thus not a
result of conscious effort at synchrony, but rather, it results from
allowing one's musical actions to be governed by innate patterns of
feeling. That is to say, you get the needed precision by playing with
passion.
This is a very important point. For Western culture has come to see passion
and precision as being antithetical. Precision is about measure and control
and so is disrupted by emotion or feeling. The physical reality of music
gives us reason to question this. For, if I am correct in my explanation of
the magic of the bell, then musical passion enhances musical precision and
is not antithetical to it.
* * * *
When I wrote that passage I was mostly interested in the physics of those
magic tones: if you have two sound waves of, say 1000 herz, how closely in
phase do they have to be to get strong constructive interference? Hence,
how closely do the motions of bell players have to be synchronized to
produce this result? I've read a little about musical acoustics, but
haven't found anything the answers to those magic tones. Beyond that, I've
shown that piece to an experienced musicologist (Charlie Keil) who also has
an interest in physical measurment of such things (though he doesn't do
such measurements himself). My suggested analysis was new to him.
However, we can't automatically rule out the possiblity that those tones
are a subjective phenomenon, caused by the nature of neural processing of
sound (such subjective phenomenon are reported in the literature).
However, I've never heard such a thing with just one bell player nor has
anyone reported such to me. So, whether the sounds interact only in the
nervous systems of the players (all the players reported hearing those
tones) or in the atmosphere, their existence does seem to be an instance of
collective control. Now, whether it is collective control for those
sounds, or those sounds are simply a side-effect of collective control for
something else (like playing together), I don't know.
But the phenomenon is quite striking.
···
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William L. Benzon 518.272.4733
161 2nd Street bbenzon@global2000.net
Troy, NY 12180 http://www.newsavanna.com/wlb/
USA
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What color would you be if you didn't know what you was?
That's what color I am.
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