[CAUT] P-12ths was: Tuning a Steinway D and a Bosendorfer Imperial together

[Richard Brekne]

I knew there was something about this sentence that bothered me... and I 
just hit on it.


        When we tune 12 tone to the octave ET we modify the tuning for
    aesthetic reasons and to deal with the change in inharmonicity
    across the scale and to
        tune the treble as sharp as we like to hear.

        Same thing with the P12th ET.

Wrong... its not the same. The whole point of tuning a P-12th tuning is 
to actually tune Perfect 12ths. Indeed... that orientation IS the 
stretch priority and our personal preferences for treble stretch are 
disposed of.  The reason the P 12th works like it does in the piano is 
that it takes each instruments inharmonicity into consideration on the 
fly. You tune D3's 3rd partial to 440... so A4 gets its fundamental to 
440.  You read the resultant 3rd partial for A4 and you tune E6's 
fundemental to that. B7's fundemental is then already decided in similar 
fashion. And of course... what these all turn out to be is different for 
each piano.  Tuning the treble as sharp as we like to hear simply 
defeats the purpose and the effects of tuning to a strict perfect 12th 
priority scheme.

Cheers
RicB