>> http://www.geocities.com/nikodamm/mayer.html.htm
>> unusual keyboard with an accidental in the far corner. (...)

> look to the archives for lengthy explanations of the typical
> south-German extended C/E short octave.
> It is not a chromatic compass.
> regards,
>
> Bill

so by 'extended C/E' we mean AA/C or GG/C, analogous to GG/BB?

I did look in the archives & never considered a chromatic compass.
Most of the messages say 'this was already discussed years ago'. The
Ur-message is:

http://listserv.albany.edu:8080/cgi-bin/wa?A2=ind9710&L=hpschd-l&P=45397

> GG/BB compass would actually be tuned GG,
> AA, AA#, BB, D#, C, F, D, G, E, a, A#, B... for instance.

based on that the lowest natural, apparently C, on the Mayer would be AA.

My question was about the little accidental which looks like it's
trying to escape off the end of the keyboard. Is that typical? Since
it tends to the left of the lowest natural it should tuned lower, thus
GG. Maybe you could tell something from where the keylevers went
inside.

That funny-looking little key is also another proof against chromatic C-c.

~~~T~~~