two strings flatter than one,

[Richard Moody]

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> From: John M. Formsma 
 
> if you strip
> mute the entire piano and tune the middle string of each note,
then come
> back and tune unisons, could we be so lucky that everything
would fall into
> place?  I don't really know, but tuning with 3-string tuned
unisons leaves
> no doubt about it.  With all three strings of the lower note
of the octave
> tuned before the upper note of the octave is tuned, you know
exactly what
> pitch you will have.

If you tune a stingle string of top note (octave) to the three
strings of the bottom note  then tune the second string to the
first, the two strings should now be slightly flat to the bottom
note.  
It seems like you would want to tune the top string to a single
string on the bottom. that should give the exact sharpness you
need to compensate for this "coupling"
(right word?) effect.   

>I quote and agree with his findings:  "...a three-string unison
> sounds at a lower pitch than a single string of that unison. 
It's easiest
> to hear this phenomenon while listening to the major 10th."
> 
That sounds like a very good reason to tune top strings to
single strings instead of all three.  This is the way I was
taught, or rather it was given as a tip, when tuning the top
octaves you might finder it easier to tune to a single string of
the bottom notes.  
.---ric