Reply to Joe Monzo on chroma

Joe Monzo wrote,

>Chroma is our perception of pitch based on periodicity
>of neural firing. In my opinion and theories, this
>involves primarily prime-factoring of the frequency
>ratios (perhaps others would admit just odd-factoring).
>So in a way, this is a kind of "sideways in pitch".

Joe, that is not the definition of chroma. Chroma is the sensation of
pitch independently of octave-specificity. The other dimension,
pitch-height, is completely octave-specific. The meaning of the
two-dimensional model of pitch to which you refer is that the
one-dimensional pitch continuum spirals its way through these two
perceptual attributes. Nothing about periodicity pitch, and _certainly_
nothing about prime factoring, is stipulated or relevant.