Extreme Sagittal JI notations - partial release

Dear Tuners,

The spreadsheet isn't quite ready yet, but here's George Secor's
marvelous chart showing the accidentals used in the various levels of
JI notation available in the Sagittal system.

http://dkeenan.com/sagittal/SagittalJI.gif

The lowest and most minimal level is the Spartan level, which is
sufficient for simple 7-limit JI and is the only level worth
memorising as its symbols are also used for many temperaments.

Then we have the Athenian level which is all that most mortals will
ever need, having the most common 11-limit pitches notated exactly and
a maximum error of 3 cents in other pitches.

Then we have increasingly god-like realms. First Promethean, which
uses all of the unaccented symbols, then Herculean which introduces
left accents corresponding to a 5-schisma shift (approx 2 cents).

Then we have the realm of the gods, the Olympian level, which
introduces the right accents, both single and double, which correspond
to various schisminas of around 0.3 cents. We expect that mere mortals
will only use this level for theoretical purposes.

-- Dave Keenan