I think Jim was correct.

According to standard, the note A below "middle C" is 220Hz.
Most tuning fork comes at this frequency.

An octave up/down is doubling/halving of frequencies.
You have 12 semitones in an octave.
And the notes follows a logarithmic scale.

So you have,

    ln k = (ln 2)/12

    where k = multiplier for the next semitone
    the constant 2 comes from the definition of what is an octave,
    constant 12 from the number of semitones in an octave.

    or k = 2^1/12

Regards,

Peter Tiang

============================================================

----- Original Message -----
From: M. Adam Davis <adavis@UBASICS.COM>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: Thursday, November 04, 1999 2:42 AM
Subject: Re: tones on piano


> I have heard, though may be incorrectly, that this is an approximation
> (much like using 3.141592653), and that the actual formulae used to
> develop the scale are somewhat more complex.
>
> -Adam
>
> Jim Hartmann wrote:
> >
> > Adjacent notes on the chromatic scale are at a ratio of 2^1/12
(1.059463).
> > Use A 440 (above middle C?) as your starting point.
>