ASA 127th Meeting M.I.T. 1994 June 6-10

3pMU9. A measurable result of bi-tri octave plate tuning.

Carleen M. Hutchins

112 Essex Ave., Montclair, NJ 07042

Many of the finest violins and violas exhibit a special quality, namely that the four quadrants of both top and back, when tapped lightly, can be heard to have approximately the same pitch. In an experiment with three violas made on the same pattern and with very similar wood, the one with bi-tri octave tuning (modes 2 and 5 at matching octaves in both top and back plates and mode 1 in the top an octave below mode 2) was found to have the above condition. The other two, with different conditions of their free plate resonances, did not. An electronic measurement of the eight quadrants in these violas, four in the top and four in the back where one would ordinarily tap, showed that the lowest two resonance peaks in each of the eight quadrants were very similar, for the bi-tri octave plate tuned viola. This was not the case in the other two which were judged by expert players to have considerably less good tone and playing qualities. These findings will be charted and their implications discussed.