Don, When you say "The method I use for pitch measurement is accurate to about 1/6000th of a cent at the low end of the piano", was that a misprint? That is equal to about one part in 10 million. Even at A-440, that means a difference of one beat in 6.3 hours! If you can read such a difference in under 10 minutes, then you must be able to detect a phase difference at A-440 of 9.5 degrees. But the note won't sound for that long without active stimulation. I have done active probing for resonsances similar to what you did for an article in the Journal, "Measuring Inharmonicity Using Continuous Excitation", June 1993. I found that the resonsant peaks, even when measured in this manner, are still too broad to define a resonant frequency to any better than about .02 cents. So 1/6000th of a cent is a bit beyond belief. Robert Scott Real-Time Specialties
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