Fractional 3-limit notation: Difference between revisions

Dave Keenan (talk | contribs)
Bad-fifths apotome-fraction notation: Changed "only justified" to "best justified" and added footnote
Dave Keenan (talk | contribs)
Bad-fifths apotome-fraction notation: Changed "simple" to "common" and added N2D3P9 rank.
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EDOs in parentheses (6), (8), (13), and (18) have fifths that are so wide they are usually notated as subsets of larger EDOs with good fifths. [59]-EDO is in square brackets because it is green not gold on the periodic table, and so it should have a JI-based notation. However, its fifth is very close to the bad-fifth threshold and its 1-step symbol is best justified<ref>In just intonation, {{sagittal| )| }} doesn't notate any simple ratio that would make it valid as 1\59. It does however notate the complex ratio 55/49 = (5·11/7²) by representing the comma 441/440 which tempers to 1\59 if only prime 3 is tempered or using the 59d map (second-best approximation of prime 7). Thanks to Roee Sinai for this JI-based justification.</ref> by the apotome-fraction notation, so its notation is a hybrid.
EDOs in parentheses (6), (8), (13), and (18) have fifths that are so wide they are usually notated as subsets of larger EDOs with good fifths. [59]-EDO is in square brackets because it is green not gold on the periodic table, and so it should have a JI-based notation. However, its fifth is very close to the bad-fifth threshold and its 1-step symbol is best justified<ref>In just intonation, {{sagittal| )| }} doesn't notate any common ratio that would make it valid as 1\59. It does however notate the uncommon ratio 55/49 = (5·11/7²) by representing, as a secondary comma, 441/440 which tempers to 1\59 if only prime 3 is tempered or using the 59d map (second-best approximation of prime 7). Thanks to Roee Sinai for this JI-based justification. 55/49 ranks 87th in popularity among 2,3-free equivalence classes of ratios, according to [[N2D3P9#Table_of_top_100_.282.2C3-equivalent.29_pitch_ratio_classes_by_N2D3P9|N2D3P9]].</ref> by the apotome-fraction notation, so its notation is a hybrid.


To obtain the Evo notations, replace the multishaft symbols above with their Evo equivalents from the previous table.
To obtain the Evo notations, replace the multishaft symbols above with their Evo equivalents from the previous table.