>...The "thrust" of the article is that any unison will *draw* one hertz due to >the coupled nature of piano strings. In other words *if* you accept the >article an error of approximately 4 cents on a unison at A4 is not only >acceptable--it is the *best* that can be done by ear alone, without >resorting to using a third note as a *referrance* or *test* interval (e.g. >17th below) . I don't think that many people would agree with that. > >Don Rose If you are referring to the article, "The Coupled Motions of Piano Strings" by Gabriel Weinreich, published in the Scientific American, January 1979; then sorry, Don, this is not the thrust of the article at all. I have it in front of me and have reviewed it. In scanning it I could not find the word Hertz even mentioned. The gist of the article is, and I quote in brief, =================== "Šwhen the strings that constitute a single triplet or pair are made to sound separately, they differ slightly in frequency in a seemingly random way, even after the best piano technicians have tuned themŠ My own workŠhas focused on how these small 'mistunings,' or frequency discrepancies, contribute to the sound of the piano. Out of my work and that of other investigators has emerged a detailed picture of how the sound at first decays rapidly (the "prompt sound") and then decays slowly (the "aftersound")Š" =================== The article is completely credible and has detailed pictures to satisfy the most discriminating person on the subject of unisons and how they contribute in unexpected ways to the tone of the instrument. If this is not the article in question, my apologies. Keith McGavern kam544@earthlink.net Registered Piano Technician Oklahoma Chapter 731 Piano Technicians Guild USA
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