Hi Ken... This seems like a good clue. But I'm not sure its the same thing they are using in their respective spreadsheets. In anycase refering to the relevant paragraph in McFerrin there is the Inharmonicity Coefficient and it does indeed vary with the density of the wire. It is designated as "B" Curiously there is a simplification that I think yields an odd way of arriving at the Youngs Modulus (Q) if one first knows the density (D) of the material. Page 43 of McFerrin.... gives two equations for B, one the result of putting in the values of Q and D, the other with these unknown. These two variations then form an equivalence if I am not mistaken... so B = (1731 * pi^2 *d^2 *Q)/(2 * 64 * f^2 * L^4 * D) = (3.4 * 10^13 * d^2)/( f^2 * L^4) If you simplify these equivalence you end up with Q = (2 * 64 * 3,4 * 10 ^13 * D) / (1731* pi^2) which works out to Q = 2,54737025541 * 10^11 * D He doesn't specify what units of volume D are figured in as far as I can see. Anyways... it would seem you can figure the Youngs modulus directly from the density of the the string material using the constant 2,54737025541 * 10 ^11 That is unless I'm off my bonkers again...:) Cheers RicB Hey, Alan & Ric, I believe Ric is asking about the inharmonicity constant. I don¹t know if that is the name used by engineers, but that¹s what I have heard it called. It relates length, diameter, and tension to predict the inharmonicity of a particular string/note. PScale used it to generate an inharmonicity number for each note, and ETDs use it to build their stretch curves. I have only seen one value referring to music wire in general, and I have wondered whether it might be different for Mapes vs Roslau. I would certainly expect Pure Sound to be different. I can¹t lay my hands on a precise value, though. Ron? Del? I¹m getting in over my head here! Bail me out! Regards, Ken Z.
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