She is hearing the 10th partial which may very well be quite sharp relative to C5. Inharmonicity provides the difference. Weman generally are more sensitive to the higher partials so you have a perception problem. Use C1 and from C5 tune the octaves going down, check your double, treple octaves and she may percieve the beats of the octaves as you tuning them out then back in. By the time you get to C1 she may be convinced your tuning is good but the piano may have some problems with inharmonicity. You will need to spend some time and explain the causes and usefulness of inharmonicity and that all tuning is a compromise between what we like to hear and what the piano produces. She will learn about tuning, about your skills and have a respect for what you do. Newton nhunt@rci.rutgers.edu
This PTG archive page provided courtesy of Moy Piano Service, LLC