From: johnl@yang.earlham.edu (John Fiskio-Lasseter)
Newsgroups: rec.music.folk
Subject: Re: Modes; was: Re: Reading music - book sought.
Date: 19 Dec 92 16:00:32 GMT
 <1992Dec18.061722.7118@das.harvard.edu> <BzGnuD.5xM@dcs.glasgow.ac.uk>
Organization: Earlham College, Richmond, Indiana

In article <BzGnuD.5xM@dcs.glasgow.ac.uk>, jack@dcs.glasgow.ac.uk (Jack Campin) writes:

>> Doesn't help that the notation leaves out steps; you're supposed to remember
>> that there's a 1/2 step between notes a&b but a whole step between notes
>> x&y, but both pairs are written one gradation apart on the paper.
> 
> This is because Western music notation was developed for Gregorian chant,
> which didn't have black notes and always used the scale of C (with different
> ranges and tonal centres depending on the mode).  The extra notes were added
> later; first B flat, then F sharp, then the rest.  It was centuries before
> anybody wrote music that was very far from the C scale, so there was no
> incentive to come up with a notational scheme that treated all notes equally.

Actually it is because of Gregorian chant and the strict rules of 
composition which were applied to it that we have sharps and flats in 
Western music.

Sometime around the the beginning of the 10th century, the first form of 
poliphony was introduced to western music -- organum.  In its earliest 
form, this kind of poliphony involved two melodic lines:  the "vox 
principalis" (the tenor, or main melodic line), and the "duplum", which 
matched the tenor note for note, a fourth or fifth down.

The problem you run into is this:  if parallel 4ths or 5ths are carried on 
long enough within the same mode, you will eventually get a tritone -- an 
interval of exactly three whole steps apart (right in the "middle" of a 
scale) -- B and F, for example.  The tritone is the most dissonant 
interval there is (within western music), and was forbidden in chant, 
often referred to as "diabolus in musica" ("the devil in music"). 

It could be avoided simply increasing or decreasing the interval to 
another note in the mode, but then the parallel is lost.  One could avoid 
any note whose parallel would be a tritone, but this made for ugly melodic 
lines. 

The solution was to augment or diminish one of the two notes by half the 
distance to their nearest neighbor, thus preserving (almost) the parallel 
lines.  Out of this came the western convention of sharps and flats.

One of the constantly fascinating aspects of this story is the cultural 
differences it highlights.  The tritone is widely used in the traditional 
music of eastern Europe.  Its prominence in the traditional music of 
Hungary had a great deal of influence on the Hungarian composer Bela 
Bartok, who employed the tritone extensively in his compositions.  Yet 
many westerners find Bartok's music ugly and unpleasant.  As I know next 
to nothing about Hungary, I'm not sure how they view him there, but I 
imagine he is a lot more accessible. 

Peace,
-- John
+---------------------------------------------------------------------+
|John Howard Eli Fiskio-Lasseter  |     "Is obair-la\ to\iseachadh"   |
|e-mail: johnl@yang.earlham.edu   |    ("Beginning is a day's work")  |
|        JOHNL@EARLHAM.BITNET     |                --Gaidhlig Proverb |
+---------------------------------------------------------------------+
Organization: University Libraries - E&S Library, Carnegie Mellon, Pittsburgh, PA