[net.music] Tempered scales

isbell@marvin.DEC (Chris Isbell ) (03/07/84)

<Mystical line>

Quote from seismo!tiberio:

>Is there any need for a discussion on the virtues of untempered scales
>(as played by woodwinds, they go flatter in the higher octaves) verses
>tempered scales (played by ugg pianos, they go sharper).
>
>learn to play a flute!

The classic work on this subject is by Hermann Helmholtz, On the 
Sensation of Tone. There is a translation published by Dover in 
paperback. It is heavy going, but worth it if you are interested in the 
subject.

In general modern woodwind instruments are tuned to the equal tempered
scale, the same at modern keyboard instruments. Early woodwind
instruments (recorders, capped reeds etc.) give the player much greater
control of the pitch. I can vary the pitch of a note by about a semitone
each side of normal on most of my capped reed instruments. In general
flutes (fipple and transverse) tend to be sharp in the higher registers
when played by unskilled players (just listen to a class of school
children playing recorders!). If you wish to go flat in the upper
registers, take up a reed instrument or a member of the violin family. 

The greater variation in pitch of early woodwind instruments has two 
effects. Firstly, an inexperienced early music consort is usually out of 
tune. Secondly, a good consort will play in non-equal temperament - 
usually just intonation. This means that the pitch of some notes of the 
scale change in pitch as the music changes key.

The reason for having different temperaments is complex, but briefly, I
is a result of the fact that roots of two are irrational numbers. The
octave, which is the most basic musical interval is a frequency ratio of
2:1. Any attempt to divide the octave into a finite number of equal
frequency ratios will result in intervals which are based on roots of
two. If the octave is not divided into equal ratios, than certain keys
will be out of tune. However, the musical intervals which are pleasing
to the ear are simple frequency ratios such as 2:3 (fifth), 3:4 (fourth),
4:5 (major third) etc. Any deviation from simple ratios will cause
interference between the two sound sources which, if the deviation is
small, results in a beating sensation. The modern equal tempered scale 
has a frequency ratio between semitones of the twelfth root of two. This 
means that certain intervals are out of tune. In particular, the major 
third is too wide. My subjective feeling is that this produces a harsh 
edge to the music which I find unpleasant.

			Chris Isbell.
    		(...decwrl!rhea!marvin!isbell)

ken@ihuxq.UUCP (ken perlow) (03/07/84)

--
>>> ...Any deviation from simple ratios will cause
>>> interference between the two sound sources which, if the deviation is
>>> small, results in a beating sensation. The modern equal tempered scale 
>>> has a frequency ratio between semitones of the twelfth root of two. This 
>>> means that certain intervals are out of tune. In particular, the major 
>>> third is too wide. My subjective feeling is that this produces a harsh 
>>> edge to the music which I find unpleasant.

>>> 			Chris Isbell.
>>>     		(...decwrl!rhea!marvin!isbell)

So do I.  After an evening with my viol consort I can't go home and
listen to Mozart.   Actually, my beef with recordings of Mozart's
symphonic music is that it sounds demented when played by a 102 piece
orchestra and those damned modern instruments.  The worst offender is
modern violin construction and technique: The piercing screech and wide
vibrato totally mask the beautiful interplay of, for example, the
last movement of the Jupiter.  If you haven't heard music of the
Baroque and Classical periods performed on Baroque instruments, you
have not heard it at all.
-- 
                    *** ***
JE MAINTIENDRAI   ***** *****
                 ****** ******    07 Mar 84 [17 Ventose An CXCII]
ken perlow       *****   *****
(312)979-7261     ** ** ** **
..ihnp4!ihuxq!ken   *** ***

ark@rabbit.UUCP (Andrew Koenig) (03/07/84)

Pianos are generally tuned with "stretched octaves."  In other words,
the high notes on the keyboard are slightly higher than one would
expect and the low notes are slightly lower.

Perhaps one reason for this is that the upper partials of an individual
piano string are also stretched:  the second harmonic (say) is very
slightly more than twice the frequency of the fundamental.  It would
therefore make sense to tune the upper notes to match the actual harmonics
of the lower notes.

The out-of-tune harmonics are one of the things that makes a piano sound
like a piano.

peters@cubsvax.UUCP (03/08/84)

Just a followup to the subject of temperment.  It is easy (technically)
for vocalists and players of unfretted string instruments to play
in just temperment (the natural harmonic scale).  I used to sing
(many years ago) in the Renaissance Chorus of N. Y.  (anyone out
there remember it?), and our director used to spend great amounts
of time trying to make us sing natural harmonic intervals.  When
you "lock in" to a perfect unison, octave, fourth, or fifth, there's
a resonance effect -- a diminution of the effort to sing the note --
that's almost euphoric.  Problem is, most people with musical training
have grown up with the piano and the well-tempered scale.  Those 
people had a lot more trouble singing true intervals, and doing it
without vibrato, so that the director found it easier to work with
people with only minimal prior training.

{philabs,cmcl2!rocky2}!cubsvax!peters            Peter S. Shenkin 
Dept of Biol. Sci.;  Columbia Univ.;  New York, N. Y.  10027;  212-280-5517

graham@parsec.UUCP (03/11/84)

#R:decwrl:-608200:parsec:39000002:000:1067
parsec!graham    Mar 10 14:10:00 1984

..
> Just a followup to the subject of temperment.  It is easy (technically)
> for vocalists and players of unfretted string instruments to play
> in just temperment (the natural harmonic scale).  I used to sing
> (many years ago) in the Renaissance Chorus of N. Y.  (anyone out
> there remember it?), and our director used to spend great amounts
> of time trying to make us sing natural harmonic intervals.  When
> you "lock in" to a perfect unison, octave, fourth, or fifth, there's
> a resonance effect -- a diminution of the effort to sing the note --
> that's almost euphoric.
 
The sound judges of SPEBSQSA (Society for the Preservation and
Encouragement of Barber Shop Quartet Singing in America) call
that euphoria "expanded sound".  SPEBSQSA quartets and choruses
sing in the style you suggest, but matching the vowel sounds as
well as tuning the intervals is required to maximize the euphoria.
Try it, you'll like it.

Marv Graham; ConVex Computer Corp. {allegra,ihnp4,uiucdcs,ctvax}!parsec!graham

PS: look up your local SPEBSQSA chapter in the phone book

mcmillan@eosp1.UUCP (Tobias D. Robison) (03/11/84)

To put it more simply, when playing or hearing harmonic music,
humans clearly prefer untempered intervals.  A singer or string instrument can
easily play untempered pitches, and can easily shift to other untempered
scales when the music modulates.  Wind players can do this only with great
difficulty, and the piano (and similar instruments) can only be tuned for
one untempered scale (and a very limited modulation capability) at one time.
Therefore, musicians are trained to play temepered scales.  However,
untempered sounds can be much sweeter, and certainly occur in unaccompanied
vocal music.

One summer I tuned a harpsichord to an untempered scale, and played quite
a bit of baroque music on it.  I liked the sound very much, but I had to be
very selective about the keys (and degree of modulation) of the music I
played.
					- Toby Robison
					allegra!eosp1!robison
					decvax!ittvax!eosp1!robison
					princeton!eosp1!robison
					(NOTE! NOT McMillan; Robison.)

isbell@marvin.DEC (Chris Isbell ) (03/22/84)

[Mystics line]

Quote from Jim Janney:

>Any woodwind instrument, however well made, is the result of many
>compromises between tuning conflicts and has many notes that sound out
>of tune. The player must make adjustments to correct for these. In
>general, the size of these adjustments far outweighs the differences
>between the even-tempered scale and more natural scales.

Wot I think:

I agree fully with the first two points, but I am less certain if the 
compromises in the instrument outweigh the errors inherent in the equal 
tempered scale. According to my calculations, the equal tempered major 
third has a frequency ratio of 1.2599..., while the just third is 
exactly 1.25. This is an error of 0.8 percent. (An error of a whole 
semitone is 6 percent.) I have not taken any scientific measurement of 
the tuning errors in modern woodwind instruments, but my subjective 
experience is that this error *is* significant. I find it much easier to 
play in just intonation on a recorder compared to a modern flute. Also, 
my feeble attempts at playing other modern woodwind instruments are, in 
general, fairly in tune (equal tempered) which again suggests to me that 
the errors inherent in equal tempered scales are significant.

Does anyone have any data on the actual tuning errors found in woodwind 
instruments?

Asides:

I have a number of the cheaper Moeck wooden recorders. On these, the 
whole instrument has been made slightly flat, and the A has been 
sharpened to bring it up to concert pitch.

If you want to scare animals or make a fool of yourself, try playing a 
French Bombarde.

			Chris Isbell.
    		(decwrl!rhea!marvin!isbell)


------- End of Returned Message

geoff@callan.UUCP (Geoff Kuenning) (03/25/84)

Chris Isbell says:

>	According to my calculations, the equal tempered major 
>	third has a frequency ratio of 1.2599..., while the just third is 
>	exactly 1.25. This is an error of 0.8 percent. (An error of a whole 
>	semitone is 6 percent.) I have not taken any scientific measurement of 
>	the tuning errors in modern woodwind instruments, but my subjective 
>	experience is that this error *is* significant.

Indeed, this should be significant.  Piano tuners measure tuning errors as a
percentage of a semitone, called 'cents'.  My tuner tells me that the human
ear can distingish half a 'cent' in tuning error (when comparing two notes);
this works out to a 0.03 percent error using the units of the paragraph
above.  A 0.8 percent error works out to about 13 'cents'.  My piano was
recently 20 'cents' out of tune, and it was *GROSS* to my ear.

Incidentally, I note that some of this apparently depends on ear training.  As
a modern listener, I find that most early instruments sound out-of-tune.  I
always attributed this to their being harder to play, but apparently this is
actually because I have learned to prefer equally-tempered scales to
"correctly-tuned scales".

	Geoff Kuenning
	...!ihnp4!sdcrdcf!trwrb!wlbr!callan!geoff