temperaments - choosing ? stretched ? not stretched ?

Andrew and Rebeca Anderson anrebe@sbcglobal.net
Sun, 12 Feb 2006 08:53:46 -0600


---------------------- multipart/alternative attachment
Phillippe,
I am not sure what you mean by a "stretched temperament."  Tuning is 
stretched on a piano because of inharmonicity caused by the stiffness 
of piano wire.  When the wire subdivides vibrations after being 
struck by the hammer it does so losing a little length with each 
subdivision because the wire is stiff.  The higher the partial, the 
more length is lost and the sharper the coincident tone.  When tuning 
a piano aurally, stretch occurs naturally as you match those 
partials.  You hear the tone blossom or open up, if you will, as you 
come into coincidence.  Where you place it in that narrow zone is a 
matter of taste--narrow, middle or wide.

Because different pianos are scaled (choice of wire size) 
differently, no one recording of reference tones will work throughout 
the compass.  Sometimes manufacturers will "refine" their scaling in 
a given model more than once in a year and the same model of piano 
will actually have a different scale.  The result of different scales 
is different tuning sometimes obvious at the extreme ends of the 
compass.  The pianos will not harmonize to a greater or lessor 
degree.  Actually, a lot of scaling refinement happens at the break 
from the long bridge to the bass bridge and the break from wound 
strings to unwound strings.

An example of how scaling differences can show up in real life 
happened at a university where my wife worked as a pianist.  They had 
a NY Steinway D and a Bosendorfer concert grand.  For a concert they 
chose to have four-hand, two piano accompaniment of the mass 
choir.  I was attending the concert and during an intermission the 
choral director approached me and asked/complained why their tuner 
couldn't get the pianos in tune with each other.  Knowing the person 
in question was a fine, pre-eminent technician, I knew the problem 
wasn't the tuning and asked about the pianos.  I explained how 
different piano makers would scale their instruments differently 
pursuing different philosophies of sound and that in order for a 
piano to be "in-tune" the resulting scales must be tuned 
differently.  The only perfectly harmonious note she could count on 
would be A4, middle A.  (Even then such different pianos would 
respond to climate differently and go out of tune 
differently.)  Steinway with its low tension scale and Bosendorfer 
with its high tension scale were destined to clash.  Those 
piano-makers have very different goals they accomplish with their 
instruments.  The university has since purchased another Steinway D.

This is why guitar tuners do not work for tuning pianos.  Piano 
tuners are more complex and cost multiples of an ordinary 
tuner.  There are a variety of electronic tuners offered explicitly 
for tuning pianos.  The cheap ones have stretch templates that may or 
may not do a good job of "parodying" the piano you are tuning.  The 
mid-level ones sample three notes on a piano and then calculate a 
stretch curve for the entire piano.  The high-end one measures each 
note you tune and fits it into the scale based on the measurements 
and records those measurements along with partial strength to 
influence the placement of other notes.  Scaling breaks occur at many 
places in the piano.  Every time you change wire size, you have a 
scaling break.  That will influence tuning.  People who tune relying 
strictly on their ETD will find that aural checks of an FAC type ETD 
will reveal tuning problems on pianos that have prominent scaling 
breaks (usual in little pianos).

As to temperament preferences, Equal Temperament is the most 
dissonant temperament.  It is also the most flexible temperament, 
allowing transposition without changing the character of a musical 
piece.  The further you wander from equal towards just temperament 
the more consonant common keys and intervals will become.  This comes 
at a price.  The dissonance will be confined more and more into 
increasingly dissonant keys/intervals.  The repertoire becomes more 
and more constrained by the tuning.  I like well-temperaments.  I've 
enjoyed Barnes Bach on a piano for some time.  The piano sounded much 
better and more powerful as many intervals were close to 
consonant.  The difficulty was in the more modern 
repertoire.  Debussy came across more like sand-paper then the 
creamy/dreamy sounds you expect from this composer.  Composers that 
utilized unequal temperaments wrote pieces that took advantage of 
those inequalities.  When you switch keys in Mozart, Beethovan, Bach 
etc. you audibly switch gears in a well-temperament.  Modern 
composers wrote for what they heard on the piano, some advocated for 
ET.  Understand what you are getting when you choose a tuning and 
then make your choice.

Good luck,
Andrew Anderson

At 06:30 AM 2/12/2006, you wrote:
>Hi all,
>
>I'm currently studying temperaments, and I wonder if a tuner always 
>use a stretched temperament,
>especially since this doesn't seems quite compatible with the use of 
>electronic tuning devices.
>(for the not aural tuners...)
>
>This question, especially since I've a CD with reference tones for a 
>stretched temperament, which
>seems quite strange since a stretched temperament should depend on 
>the kind of piano, shouldn't
>they ? So what ?
>
>subsidiary question : as a tuner, do you prefer to use equal 
>temperament ? or do you prefer to use
>another one ? (which one) ... Or do your clients often have their 
>specific requests ? (in this case
>what are you commonly asked ?)
>
>Philippe Errembault


---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/62/44/4a/5b/attachment.htm

---------------------- multipart/alternative attachment--


This PTG archive page provided courtesy of Moy Piano Service, LLC