Normally stretched treble sounds flat

[Daniel Gurnee]

on 2/24/01 9:31 AM, John Baird at jbaird@fgi.net wrote:

> Thanks Fred and others,
> 
> I have been stretching a lot more since your responses started coming in.
> 
> I did find a few thoughts from Jim Coleman, Sr. in an article called CHASING
> THE WOLF, Thoughts Towards a New Perspective
> on Octave Stretching" in the June 1996 PTJ...
> 
> "Let’s digress for just a moment to add one more item to the
> mix. In many classes at Seminars and Institutes, a demonstration
> has been made between the melodic sense of hearing and the
> harmonic sense of hearing. The demo usually went something
> like this:
> The note C3 was played and everyone was encouraged to
> listen carefully and remember that sound. Then C7 would be
> played and tuned until there was a 70 percent to 80 percent
> agreement that the pitch was correct. Then with the use of an
> electronic measuring device, the note would be found to be 25 to
> 50 cents sharp. Now this is much sharper than anyone known to
> the writer would even dare to tune. It is even much higher than the
> 16th partial of C3 would require on many pianos. This demonstra-
> tion shows that the subjective judgments made using the melodic
> (one note followed by another) sense of hearing requires sharper
> tuning than does the harmonic sense (one or more notes played
> together).
> Now, there is no way that the melodic sense of hearing is going
> to be completely satisfied in piano octave tuning in the treble.
> However, demonstrations made recently show that much greater
> sharpening of the treble can be tolerated harmonically than was
> previously thought possible. With the advent of the new FAC
> stretch tuning on the Accu-tuner, technicians are becoming
> accustomed to hearing pure 4-1 type double octaves to the top end
> of the piano. 

The top octave of a pure 4-1 double octave is a pure unstretched 2-1 octave
which contributes little to stretching anywhere in the scale.



At a recent convention, a concert was heard where
> the top C8 was tuned over 50 cents sharp, with proper gradations
> below supporting it. It sounded great. This writer has suspected
> that in growing older perhaps his hearing may be the problem, so
> younger ears have been employed in some of the tests, yielding the
> same conclusion that sharper tuning does sound better."
> 
> Thanks again,
> 
> John Baird
> 
> Fred Sturm wrote:
> 
>> John Baird wrote:
>>> 
>>> Alternate Subject Line:   Outrageously stretched treble sounds great
>>> 
>>> RE: The phenomenon where a normally, RPT-exam-passing, stretched treble
>>> sounds flat, especially when playing a slow arpeggio up to the top
>>> octave, but an extremely stretched treble sounds very good. The single
>>> octaves, 10ths & 17ths don't pass an inspection by tuners, but the piano
>>> does sound great when it is played.
>>> 
>>> I believe this has been discussed before--does anyone remember when or
>>> what the subject line was?
>>> 
>> There was an article in the PTJ some years ago entitled (I think)
>> "Picasso Tuning" and the thread may have had that title. I remember a
>> discussion along these lines on Pianotech about four years ago. Jim
>> Coleman contributed quite a bit, including his "pure 5ths" temperament,
>> which he later turned into PTJ articles.
>> I personally tune a triple octave stretch on concert grands and any
>> other piano whose inharmonicity allows (a judgment call, and the variety
>> is quite broad). I find this stretch, which produces rather fast beating
>> "single" (2:1) octaves, and 3rd/10th, 10th/17th and 3rd/17th tests with
>> pretty wide differences in beat rates in some parts of the scale (again,
>> varies tremendously depending on inharmonicity curve) creates a more
>> brilliant and generally pleasing sound overall. Pure double octave
>> stretch, which is very reliably produced by SAT FAC tunings, is quite
>> nice and clean, but not as "interesting" and "vibrant." But frankly, I
>> don't think triple octave stretching  is very "radical" in sound. None
>> of the octaves or double octaves sound bad unless you focus the ear on
>> listening for beats. I suspect wider than triple octave could be quite
>> acceptable in many circumstances.
>> Trouble is, it seems most discussion focuses on anecdotal evidence,
>> with no quantification to back it up. It would be interesting to do a
>> series of tuning comparisons somewhat like what Jim Coleman and Virgil
>> Smith did a couple years back, varying tunings by perceptible and
>> measurable stretch constants consistently applied.
>> Fred Sturm
>> University of New Mexico
> 
>