Re: Western world tunning?


Subject: Re: Western world tunning?
From: Richard Wentk (richard@skydancer.com)
Date: Fri Jun 18 2004 - 13:59:22 EDT


At 10:14 18/06/2004 -0700, you wrote:
>Hello,
>Somebody recently asked me why the western world divides up our octave
>into twelve portions? I began to research on the web only to find that
>the majority of files basically said "Its just because it is" or they over
>estimated my vocabulary skills (mesuring the interval in Cents?).
>I was wondering if anyone could tell me, or point me in the right
>direction of information:
>-why it is divided into 12 semitones,

The idea that there are 12 equidistant semitones with absolute defined
frequencies is only really true for keyboard instruments. Most singers and
non-keyboard instrumentalists will more or less consciously vary intonation
according to context, so the intervals are really rather fuzzy things.
(Except on digital synthesizers.)

It's not even true for pianos, because stretch tuning means the octaves
aren't perfect.

>-why do different parts of the world have more intervals in an octave...

If your music is based on the harmonic series there are only certain
divisions of the octave that produce intervals that relate to the series.
In theory there's no reason not to use other divisions like 17 or 23 or any
number you can think of. But the trade off is between controllability and
overtone accuracy. Given fingers and hands of a certain width and a desire
to tune to harmonic intervals, twelve works as a good compromise.

If you take away the harmonic requirement, as some cultures do, you end up
with very different scales. I've seen it suggested that in something like
Balinese gamelan the intervals are based on the non-harmonic partial series
made by the gongs they play - but I haven't checked this in detail.

Richard



This archive was generated by hypermail 2b27 : Sat Dec 22 2007 - 01:46:02 EST