Standard Pitch (A440).  Where did it come from?  Has the standard changed over time? If so, which one, if there is such a thing, is correct or true?  Does it matter?  If it does matter, how so?  Is there evidence in nature as to what is most natural as

Standard Pitch (A440).  Where did it come from?  Has the standard changed over time? If so, which one, if there is such a thing, is correct or true?  Does it matter?  If it does matter, how so?  Is there evidence in nature as to what is most natural as to