45edo: Difference between revisions
Dave Keenan (talk | contribs) →Sagittal notation: Moved the explanation of ≈ to the end of the section. |
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{{EDO intro|45}} | {{EDO intro|45}} | ||
== Theory == | == Theory == | ||
45edo effectively has two major thirds, each almost equally far from [[just]], but as the flat one is slightly closer, it qualifies as a [[meantone]] temperament, forming a good approximation to [[2/5-comma meantone]]. It is the [[optimal patent val]] for [[flattone]] temperament, the 525/512 [[planar]] 7-limit [[Avicennmic_temperaments|avicennmic]] temperament, the 11-limit [[calliope]] temperament tempering out [[45/44]] and [[81/80]], and the rank four temperament tempering out 45/44. It tempers out 81/80, 3125/3087, 525/512, 875/864 and 45/44. It is a flat-tending system in the [[7-limit]], with 3, 5 and 7 all flat, but the 11 is sharp. | 45edo effectively has two major thirds, each almost equally far from [[just]], but as the flat one is slightly closer, it qualifies as a [[meantone]] temperament, forming a good approximation to [[2/5-comma meantone]]. It is the [[optimal patent val]] for [[flattone]] temperament, the 525/512 [[planar]] 7-limit [[Avicennmic_temperaments|avicennmic]] temperament, the 11-limit [[calliope]] temperament tempering out [[45/44]] and [[81/80]], and the rank four temperament tempering out 45/44. It tempers out 81/80, 3125/3087, 525/512, 875/864 and 45/44. It is a flat-tending system in the [[7-limit]], with 3, 5 and 7 all flat, but the 11 is sharp. It is also the unique equal temperament tuning that [[tempers out]] both the [[syntonic comma]] and the [[ennealimma]]. | ||
45edo tempers out the [[quartisma]] and provides an excellent tuning for the 2. | 45edo tempers out the [[quartisma]] and provides an excellent tuning for the 2.7/3.33 subgroup [[The Quartercache#Direct quartismic|direct quartismic]] temperament, in which it approximates the [[33/32]] quartertone with 2 steps and [[7/6]] with 10 steps. A bit more broadly, it maps the 2.17.25.27.33.63.65 subgroup to great precision; this is the part of the [[17-limit]] shared with [[270edo]]. | ||
Otherwise, it can be treated as a 2.5/3.7/3 subgroup system (borrowing 5/3 from [[15edo]] and 7/3 from [[9edo]]) and is a good tuning for [[gariberttet]], defined by tempering out [[3125/3087]] in this subgroup, approximating 2/5-comma gariberttet. | |||
=== Odd harmonics === | === Odd harmonics === | ||