Talk:2.3.7 subgroup

retraction/expansion terminology

I know this is well-defined on temperaments, but for subgroups, I would prefer the more well-known terms restriction/extension.

– Sintel🎏 (talk) 23:18, 22 April 2025 (UTC)

It seems necessary to consider the relationship with Group extension. (Can group extension be used in relation to 2.3.5 and 2.9.5?) ... Oh dear, there's also Retract (group theory).

Retraction seems like it could be directly used in the definition of saturation. --Dummy index (talk) 12:01, 23 April 2025 (UTC)

That's a lot of abstraction for what is essentially very simple: extension = make bigger, restriction = make smaller. – Sintel🎏 (talk) 20:33, 23 April 2025 (UTC)

I asked Claude 3.7 and was convinced that group extension can be used for weak 'extension'. (It's not that I understood cohomology or anything like that.) To return to the topic, I agree to put aside retract, which is similar to both saturation and projection. --Dummy index (talk) 15:00, 24 April 2025 (UTC)

We need to moderate color name usage

I firmly believe that color names should never be the exclusive names used to refer to something. TallKite does not own the wiki, and descriptions should be provided in familiar musical terms (or terms derived from such) where possible (even if color names are provided as alternatives).

P.S. I do not think "subminor" on a page about the 2.3.7 subgroup is ambiguous in the slightest.

-- VectorGraphics (talk) 21:28, 11 June 2025 (UTC)

Ok, let's have another go at this

Type	Color name	Quality	Intervals	Notes
Pentatonic	zo (2.3.7, 7-over) pentatonic	Subminor	1/1 7/6 4/3 3/2 7/4 2/1
Pentatonic	zo in	Subminor (in)	1/1 9/8 7/6 3/2 14/9 2/1	in scale, a minor scale with no 4th or 7th
Heptatonic	zo heptatonic	Subminor	1/1 9/8 7/6 4/3 3/2 14/9 7/4 2/1
Heptatonic	za (2.3.7) harmonic minor	Subminor (harmonic)	1/1 9/8 7/6 4/3 3/2 14/9 27/14 2/1	zo scale with a ru 7th
Pentatonic	ru (2.3.7, 7-under) pentatonic	Supermajor	1/1 9/8 9/7 3/2 12/7 2/1
Heptatonic	ru heptatonic	Supermajor	1/1 9/8 9/7 4/3 3/2 12/7 27/14 2/1
Enneatonic	- (zo)	Subminor (diasem)	1/1 9/8 7/6 21/16 4/3 3/2 14/9 7/4 16/9 2/1	diasem/Tas[9] (left-handed)

Proposal for replacement for the scales section. -- VectorGraphics (talk) 22:40, 15 October 2025 (UTC)