A440 under fire

[Richard Moody]

Hi Rich A

    Interesting mention of Helmholtz and physical pitch of C 256.   The
conclusion I am drawing is that 256 is  2^8.  At A440  C is 261.63.    Hmmm
I wonder what it was at A435?    And then that doesn't mean much because if
organs were traditionally tuned in Meantone centered on C then A would be a
hair above a Major 6th (5/3) up.(426.6 from 256) Somewhere I heard or read
that the reason A 435
got changed to A440 was that A440 was close to an ET Sixth above C in ET
instead of a nearly pure Sixth above which it would have been in Meantone.
But back to 256 pitch.  Doesn't a 4 foot pipe give close to C 256 because of
the speed of sound at 70 degrees F ? It looks like it would take a 4.4 foot
pipe to give 256 at 70 degrees. At some temperature a 4 foot pipe will give
256.   FWIW  ---ric


> There is a good history of how the A=440 came to be, Helmholtz,
> physical pitch,C=256,  etc.
>
> Fun stuff....
>
> Draw your own conclusions...
>
> Rich A.
>