[pianotech] Stretch in tuning

[Ron Koval]

Les wrote:I really wish all the ETD people would somehow find ways that exact replicas
of each other's tunings could conveniently be made.
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Les, that's what we've been doing over on the Verituner forum using the custom styles. If, for example I find a particular style of tuning that REALLY seems to work for the practice room P22's, I can throw it out there for other techs to try.  I've been able to try some tuning styles that other techs like and hear for myself how they approach the puzzle.
In general terms, when an octave sounds "pure" it is stretched because of inharmonicity... What often happens when stacking octaves on top of each other is a further stretch to make the double, triple and wider octaves sing.  Hopefully, those matches are tempered by keeping the singles within reason.  Simply matching a single partial match (for example 4:2 or 6:3 match - or even a 3:1 match) won't guarantee anything other than a precise control of spreading the temperament out to the rest of the piano.
Where does this leave us?  I still feel that the hybrid tuning technique I've proposed givesa good solution to this puzzle of stretching the octaves for ETD users. It involves a little work of pretuning the octave A's and then forcing the machine to create a calculation to cross those points.  I have no idea how to possibly incorporate that into an aural tuning, though it seemsthat Bill Bremmer achieves that goal with his "mindless" octave approach...
Ron Kovalchicagoland