Dear sir: If you use the formula which you gave to Don and Andrea, you will end up a half step above where you intend. Your formula must be built upon a note one half step below the 27.5 which is 25.9565563. In your formula, if you substitute the number 1 for N you will get A#0. That' why your constant must be 25.9565563 which is a half step lower than A0. Another way to do it would be to substitute (N-1) instead of N. Jim Coleman, Sr.
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