Sagittal notation: Difference between revisions

'''Sagittal notation''' is a [[musical notation]] system capable of notating almost any conceivable tuning. It was developed by [[Dave Keenan]] and [[George Secor]] with significant contributions from numerous others.  

A sub-flavor of Evo is '''Evo-SZ''' (Evo with Stein–Zimmermann). This is where any sagittals that are notating exactly half the alteration of a sharp or flat (most often {{sagittal| /|\ }} {{sagittal| \!/ }}) are replaced by the Stein–Zimmermann semisharp {{sagittal| > }} and narrow reversed flat {{sagittal| < }}, and the corresponding combinations (most often {{sagittal| /|\ }}{{sagittal| # }} and {{sagittal| \!/ }}{{sagittal| b }}) are replaced by {{sagittal| ># }} and {{sagittal| <b }}. The narrow variants of the fractional flats {{sagittal| < }} (U+E284) and {{sagittal| <b }} (U+E285) are preferred because they preserve the Sagittal principle that the visual size of a symbol should indicate the relative size of its alteration and they reduce left-right confusion.

 

In tempered systems, Evo-SZ {{sagittal|>}} {{sagittal|<}} {{sagittal|>#}} {{sagittal|<b}} accidentals ''may instead'' be distinct from Sagittals like {{sagittal| /|\ }}{{sagittal| \!/ }}, when the apotome can be split in two equal parts as in [[Hemipyth|Hemipythagorean]] as literal half-sharps and half-flats, with a distinction between mapped neutral thirds like [[11/9|~11/9]] or  ~[[16/13]] and [[Sqrt(3/2)|hemififths]] which might be mapped to another interval like [[49/40]] in particularly fine-grained EDOs like [[270edo|270]] or [[311edo|311]]. There is no need for this in coarser EDOs like [[24edo|24]], [[31edo|31]] or [[41edo|41]], where in this case the [[243/242|rastma]] is tempered out, and thus the mappings of the irrational hemififth and [[11/9]] coincide.

The '''Revo''' flavor (short for "revolutionary", previously called "pure") only requires one accidental per note. Revo therefore takes up less space on the sheet and presents a cleaner appearance, and it clearly indicates the direction of the overall alteration. It discards the conventional sharps and flats and their doubles and replaces them with these multi-shaft arrow-like symbols: {{sagittal| /||\ }} {{sagittal| \!!/ }} {{sagittal| /X\ }} {{sagittal| \Y/ }}. Adding a sharp or flat to a Sagittal is achieved by adding two more shafts, e.g. {{sagittal| /| }}{{sagittal| # }} becomes {{sagittal| /||| }} and {{sagittal| !) }}{{sagittal| b }} becomes {{sagittal| !!!) }}, as expected. [[2187/2048#Notation|''Apotome'']] ''complements'', that arise when the Sagital accidental alters in the opposite direction to the apotome, do not have a simple rule in Revo. One must simply memorize the complements one needs, as shown below.

{{sge| ~~¦  | ~~!  | sh  |      99/88     | 49/11C }}

{{sge| ~~¦¦¦  | ~~!!!  | sh |  99/88 | 49/11C }}