If you were a horn player, you would recognize this as a natural part of the harmonic series, particularly if you were familiar with natural horn literature, i.e. for horns without valves playing only on the notes of the harmonic series, sometimes altering the pitch by the hand position in the bell. Benjamin Britten used this flat seventh to very nice effect in the Prologue and Epilogue to his Serenade for Tenor, Horn, and Strings. Frank Emerson
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