Topic: Tempérament parfait

Le tempérament égal à quinte juste va rendre votre piano parfaitement accordé (bien sûr un accordage occidental et contemporain).  Je n'ai pas inventé ce tempérament mais j'ai trouvé la formule pour l'appliquer à Pianoteq.  C'est M. Serge Cordier qui a exploré, expliqué et défini ce tempérament.  Il consiste tout simplement à rendre juste les fondamentales de toutes les quintes.  Quand on rend les octaves justes, les quintes sont forcément abaissées, ce qui  fait "pleurer" les quintes et qui crée de faux battements à travers tout le piano.  Bien sûr en rendant les quintes justes, on agrandit les octaves, mais on le ferait déjà dans les basses et les aigües dans le tempérament qu'un accordeur ferait.   Quand vous tenterez ce tempérament, vous constaterez ,au début, que les tierces ne "sonnent" pas comme d'habitude, mais vous découvrierez  que tout votre piano s'ouvre de façon extraordinaire.  Cela peut vous prendre un peu de temps pour apprécier, mais après quelques minutes, vous ne voudrez plus jamais entendre un autre accordage.  Cela peut sembler prétentieux mais vous n'avez rien à perdre. La formule est la suivante:  TEMPÉRAMENT  "FLAT" et STETCHING  1.23 .   

Bonnes musiques.

Re: Tempérament parfait

My ears and technical understanding are too limited to appreciate this information, but it sounded so fascinating to me that I couldn't resist making a quick translation of it for the non-French speaking forum dwellers.  The additions in [square brackets] are my guesses, for clarification.  Hope this helps!  Chris

----

Perfect Temperament

The just fifths equal temperament will make your piano perfectly tuned (of course, with a Western, contemporary tuning).

I did not invent this temperament, but have found the formula to apply it in Pianoteq. Mr. Serge Cordier is the one who explored, explained and defined this temperament. It simply consists in making the fundamentals of each fifth, just. When one makes the octaves just, the fifths are necessarily lowered, which makes the fifths "cry" and creates fake [artificial] beats throughout the piano. Of course, by making the fifths just, the octaves are widened [stretched], but this would already be the case anyway for the bass and treble [strings] in the temperament that a tuner would create.

When you try this temperament, you will initially notice that the thirds don't "ring" as usual, but you will then discover that your entire piano opens up in an extraordinary way. This may require a bit of time to appreciate, but after a few minutes, you will never want to hear a different tuning again. This may sound pretentious, but you have nothing to lose.

The formula is: "Flat" temperament + 1.23 Stretching

Enjoy the music.

Last edited by doobya (29-03-2010 14:19)

Re: Tempérament parfait

(Is this accurate? Does using the flat setting and putting the stretch at 1.23 actually create the Cordier temperament?)

Re: Tempérament parfait

Yes, it is flat, not equal,  at 1.23 stretch.  To make the rights thing, you must tune the piano at 439.85 hz,  not 440.00 hz.   Try to play Pianotq at this temperament with another instrument of your choice or with a CD you like.  All the range of the keyboard sound great.  My book of Serge Cordier is wright in french.  The name of the book is called  "Piano bien tempéré et justesse orchestrale", (Le tempérament équal à quintes juste).  Editor, "Buchet/Chastel  18,rue de Condé-75006 PARIS".  That book was wright in 1982, that's not a new book.

Re: Tempérament parfait

Not that I doubt you--it's just that it seems too simple. 

Re: Tempérament parfait

I think you mean "written" rather than "wright". Since it took me a while to guess I wanted to share it so others understand.

Merci pour cette information, j'ai hate d'essayer.

Stéphane Dussault wrote:

... My book of Serge Cordier is wright in french.  The name of the book is called  "Piano bien tempéré et justesse orchestrale", (Le tempérament équal à quintes juste).  Editor, "Buchet/Chastel  18,rue de Condé-75006 PARIS".  That book was wright in 1982, that's not a new book.

Re: Tempérament parfait

M. Bremmer has recently posted a translation of Cordier's tuning sequence. May be of interest, for Cordier specifies beat rates for the intervals other than the just 5ths:

http://www.pianoworld.com/forum/ubbthre...74/42.html

I haven't had the chance to see how this matches up with setting the stretch to 1.23 in PianoTeq, and I really don't trust myself to count the beats correctly. (I can count off a second, and I can count beats, but doing both at the same time is a skill I am still trying to learn...)

Re: Tempérament parfait

Jake Johnson wrote:

(Is this accurate? Does using the flat setting and putting the stretch at 1.23 actually create the Cordier temperament?)

One question for Stéphane : how did you estimate this 1.23 stretch value ?

The second question for MODARTT: what is the unit (or scale) used for the stretch value? The manual simply says:

"When the octave stretching parameter is set to 1, the stretching follows the natural inharmonicity of the strings (depending on the string length), so there still is a slight stretching. If you want no stretching at all, then use the flat temperament."

Knowing the answer to the latter, computing the answer to the former is straightforward, I believe!

More generally, is there a document that gives the units used in Pianoteq configuration parameters (taken apart obvious ones in dB or %)?

Alain

Last edited by iaoranaemaeva (07-04-2010 05:20)

Re: Tempérament parfait

Jake Johnson wrote:

Not that I doubt you--it's just that it seems too simple. 

Things are not that simple, I fear!
What I understand at the moment - please correct me wherever I'm wrong:

According to the classic theory, octave stretching is required because of higher string inharmonicity in the piano (not in other instruments e.g. organs). It is not a linear stretching: specific stretching for lower wound strings, small stretching for medium strings, maximum stretching for short strings. In Pianoteq, this stretching is automatically set with "stretching" = 1.

If we increase "string length" to 10 m, inharmonicity becomes negligible for all strings, so  stretching is no longer necessary.

Cordier's temperament is unrelated to inharmonicity: it may be superimposed to it (or vice-versa ;-) ). Hence, I doubt this combination can be accurately obtained in Pianoteq with a simple "stretching" change!

Cordier's temperament has been applied to organs

Wikipedia references:

Tempérament égal à quintes justes

This article was not translated into English, but it was briefly summarized in
Equal temperament

Last edited by iaoranaemaeva (07-04-2010 08:31)

Re: Tempérament parfait

The problem, for me, is partly just setting the bearing. From what I can tell, Cordier doesn't just set all of the intervals in the center so that the 5ths are just, or adhere to ET in the bearing and then make the fifth of every note just.

And I'm immediately lost when I try to follow the instructions for setting the bearing: I can't begin to measure "0.8 beats per second wide,"
and "1.7 beats per second wide." Looking forward to hearing from people who can. At least we'll eventually get a cents deviation chart to give us an estimate of the pitches.

Re: Tempérament parfait

Jake Johnson wrote:

At least we'll eventually get a cents deviation chart to give us an estimate of the pitches.

Here is the frequency scale given in the fr.wikipedia.org I quoted above - obviously, the perfect fifth is divided into 7 equal parts, so that a semitone interval is 1.5^(1/7) :

    * 1.0
    * 1.059634
    * 1.122824
    * 1.189782
    * 1.260734
    * 1.335916
    * 1.415582
    * 1.5
    * 1.589451
    * 1.684236
    * 1.784674
    * 1,891101
    * 2,003875

But S. Cordier and his adepts did or do not use electronic tuners, and it is likely their "beating method" yields sligtly different values.

Also, there are often confusions between pure, perfect (just) and "no beat" fifths!

To be frank, being an "ordinary" pianist, I did not study Cordier's detailed method ;-)

Re: Tempérament parfait

iaoranaemaeva wrote:

The second question for MODARTT: what is the unit (or scale) used for the stretch value? The manual simply says:

"When the octave stretching parameter is set to 1, the stretching follows the natural inharmonicity of the strings (depending on the string length), so there still is a slight stretching. If you want no stretching at all, then use the flat temperament."

Knowing the answer to the latter, computing the answer to the former is straightforward, I believe!

More generally, is there a document that gives the units used in Pianoteq configuration parameters (taken apart obvious ones in dB or %)?

Alain

Alain, there is no unit for the stretch, it is just a percentage of a default deviation (that can vary from one piano to another). This approach (percentage of a given default value) is also used for some other parameters, it is quite a direct and intuitive approach where dB would not be very relevant.

Concerning tuning, the best solution for achieving a given precise temperament is to use the detune NOTE EDIT (TUNING panel, diapason menu, clicking at the bottom on "Detune notes" gives you access to the detune NOTE EDIT). Here the deviation is in the standard "cent" unit, a hundreth of a semitone.

Re: Tempérament parfait

Merci Philippe !

Last edited by iaoranaemaeva (07-04-2010 21:49)

Re: Tempérament parfait

Bill Bremmer has continued his translation of the Cordier tuning sequence with information about tuning the octaves and the 12ths:

http://www.pianoworld.com/forum/ubbthre...20CHA.html

And he's planning to record some things with the tuning soon, it seems.

Re: Tempérament parfait

iaoranaemaeva wrote:

Here is the frequency scale given in the fr.wikipedia.org I quoted above - obviously, the perfect fifth is divided into 7 equal parts, so that a semitone interval is 1.5^(1/7)

We can check this formula is consistent with the Scala file cordier.scl :

 Serge Cordier, piano tuning, 1975 (Piano bien tempéré et justesse orchestrale)

  0:          1/1               0.000  unison, perfect prime
  1:        100.279 cents     100.279
  2:        200.559 cents     200.559
  3:        300.838 cents     300.838
  4:        401.117 cents     401.117
  5:        501.396 cents     501.396
  6:        601.676 cents     601.676
  7:          3/2             701.955  perfect fifth
  8:        802.234 cents     802.234
  9:        902.514 cents     902.514
 10:       1002.793 cents    1002.793
 11:       1103.072 cents    1103.072
 12:       1203.351 cents    1203.351

Also, we can notice its stretching is much wider than in CHas:

CHas s=1
  0:          1/1               0.000  unison, perfect prime
  1:        100.038 cents     100.038
  2:        200.077 cents     200.077
  3:        300.115 cents     300.115
  4:        400.153 cents     400.153
  5:        500.192 cents     500.192
  6:        600.230 cents     600.230
  7:        700.268 cents     700.268
  8:        800.307 cents     800.307
  9:        900.345 cents     900.345
 10:       1000.383 cents    1000.383
 11:       1100.422 cents    1100.422
 12:       1200.460 cents    1200.460

Re: Tempérament parfait

"...Also, we can notice its stretching is much wider than in CHas."

I'll have to check the Scala file later, but I do worry that the thirds are going to be awfully wide. That's one thing I like about Alfredo's slightly narrow, consonant 12ths across the keyboard--they keep the thirds from getting too far out of control.

In fact, I've been going in another direction, experimenting with temperament ordinaire as outlined by Rousseau--a departure from meantone that seems to have a wolf on close voiced chords that include an Ab (if I'm tuning it correctly), but which has great thirds and fifths and brings out some interesting resonances if I spread it from the center with 12ths similar to Alfredo's. I'll post a file once I'm more sure I have it right. But let's hope we can get Cordier set up to have a listen.

Do you know of recordings in Cordier? (With CHas, the recordings let us know what we were after.)

Last edited by Jake Johnson (08-04-2010 14:40)

Re: Tempérament parfait

Jake Johnson wrote:

(..) I do worry that the thirds are going to be awfully wide.

Indeed!

Do you know of recordings in Cordier?

I don't. I briefly browsed the Internet with keywords "cordier piano enregistrement" (or "record" or "recording"), but did not find any relevant reference.

In passing, I found an interesting (I mean scientifically conducted ;-) ) experimental study to be presented at "10ème Congrès Français d'Acoustique, Lyon 12-16 April 2010":
Objectivation de la perception du tempérament : l'accordage du piano
Unfortunately, there is no English translation of this paper (not even its summary!).

In a few words, those blindfold tests (made with an acoustic piano, tuned according to standard equal temperament, then Cordier's temperament) show Cordier tuning was mostly preferred on recorded samples of  Rachmaninov, Debussy and even Bach short pieces. Standard equal temperament was never significantly preferred.

[EDIT] Thanks to Pianoteq's Scala import function + A/B switching, it is easy for each of us to compare Alfredo's and Cordier's temperaments! Personally, my first attempts tend to favor Alfredo...

Last edited by iaoranaemaeva (08-04-2010 20:43)

Re: Tempérament parfait

Stéphane Dussault wrote:

Yes, it is flat, not equal,  at 1.23 stretch.

Please elaborate!

(sans rancune Stéphane ;-) )

Re: Tempérament parfait

Actually, I'm wrong to worry about the thirds--meantone temperaments have wide 5ths without stretching the thirds out of shape too much.

I was thinking, not clearly, that wide fifths would mean that other intervals would be wide, but the opposite has to happen, or the octave would get too wide.

Re: Tempérament parfait

For me "temperament parfait" is an ET but not the classical one, nor those of Serge Cordier or Bernard Stopper...
In principle with different values of the half-tone, we can use millions of different ET's. The principal question is:
how large must be this step?! I propose here my concept of ET and hope to have many opinions about it! Thanks!

! Dimitrov.scl
!
Latchezar Dimitrov 2020 Moyen half tone equal temperament
12
!
100.27124
200.54248
300.81373
401.08497
501.35622
601.62746
701.94696
802.16995
902.44119
1002.7123
1102.9836
1203.2548