1/2-comma meantone: Difference between revisions

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In '''1/2-comma [[meantone]]''' temperament, each perfect fifth is tempered by a half of a [[syntonic comma]] from its just value of [[3/2]]. This results in minor sevenths being exactly [[9/5]] (and major seconds being exactly [[10/9]]).
'''1/2-comma meantone''' is the tuning of [[meantone]] temperament in which each perfect fifth is tempered by a half of a [[syntonic comma]] from its just value of [[3/2]]. This results in minor sevenths being exactly [[9/5]] (and major seconds being exactly [[10/9]]).


In this system, the "major thirds" are exactly [[100/81]] or approximately 365 [[cent]]s, thus bordering on neutral thirds. The fifths of this temperament are even narrower than those of [[26edo]], which is the most likely candidate for a closed system approximating this meantime.
In this system, the major thirds are exactly [[100/81]] or approximately 365 [[cent]]s, thus bordering on neutral thirds. The fifths of this temperament fall between those of [[26edo]] and [[33edo]], but closer to 33, which is the best small number candidate for a closed system approximating this meantone. If you want more precision, [[125edo]] using the bb [[val]] flat 5th is audibly indistinguishable from a closed system of half-comma meantone, with an error measured in thousandths of a cent.
 
For a tuning with so flat a fifth, the 7-limit [[extension]] that preserves [[7-odd-limit]] [[diamond monotone]] is [[flattertone]]. Otherwise the septimal meantone mapping has the sizes of [[7/6]] and [[8/7]] swapped, and the flattone mapping has the sizes of [[7/5]] and [[10/7]] swapped.
 
== Tuning profile ==
[[Projection map]]:
 
{| class="right-all"
|-
| [⟨ || 1 || 2 || 4 || 10 || ]
|-
| ⟨ || 0 || -1 || -4 || -17 || ]
|-
| ⟨ || 0 || 1/2 || 2 || 17/2 || ]
|-
| ⟨ || 0 || 0 || 0 || 0 || ]]
|}
 
[[Tuning map]]: {{val| 1200 1891.2019 2764.8074 3350.4316 }}
 
[[Error map]]: {{val| 0 -10.7531 -21.5063 -18.3944 }}


[[Category:Meantone]]
[[Category:Meantone]]
[[Category:Historical]]

Latest revision as of 14:27, 7 November 2024

1/2-comma meantone is the tuning of meantone temperament in which each perfect fifth is tempered by a half of a syntonic comma from its just value of 3/2. This results in minor sevenths being exactly 9/5 (and major seconds being exactly 10/9).

In this system, the major thirds are exactly 100/81 or approximately 365 cents, thus bordering on neutral thirds. The fifths of this temperament fall between those of 26edo and 33edo, but closer to 33, which is the best small number candidate for a closed system approximating this meantone. If you want more precision, 125edo using the bb val flat 5th is audibly indistinguishable from a closed system of half-comma meantone, with an error measured in thousandths of a cent.

For a tuning with so flat a fifth, the 7-limit extension that preserves 7-odd-limit diamond monotone is flattertone. Otherwise the septimal meantone mapping has the sizes of 7/6 and 8/7 swapped, and the flattone mapping has the sizes of 7/5 and 10/7 swapped.

Tuning profile

Projection map:

[⟨ 1 2 4 10 ]
0 -1 -4 -17 ]
0 1/2 2 17/2 ]
0 0 0 0 ]]

Tuning map: 1200 1891.2019 2764.8074 3350.4316]

Error map: 0 -10.7531 -21.5063 -18.3944]