Normally stretched treble sounds flat

[John Baird]

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. 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