Comma pump - Revision history

Inthar: /* Negri */

2026-03-28T01:38:11Z

Negri

2026-03-28T01:38:02Z

Examples

2026-03-16T12:29:22Z

← Older revision		Revision as of 12:29, 16 March 2026
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	There is some ambiguity in this term depending on whether the comma in question is tempered out (thus returning to the starting pitch) or not. If the comma is tempered out, the chord progression may be called a '''comma loop'''.		There is some ambiguity in this term depending on whether the comma in question is tempered out (thus returning to the starting pitch) or not. If the comma is tempered out, the chord progression may be called a '''comma loop'''.

	Given a comma, a comma pump may be constructed by stacking root movements by basic intervals in the JI group in question to that comma. Reordering movements of a comma pump, or reversing the ~~movements~~, creates another valid comma pump progression for that comma.		Given a comma, a comma pump may be constructed by stacking root movements by basic intervals in the JI group in question to that comma. Reordering movements of a comma pump, or reversing the progression, creates another valid comma pump progression for that comma.

	== Examples ==		== Examples ==

2026-03-16T12:18:59Z

Slendric

2026-02-25T03:32:44Z

← Older revision		Revision as of 03:32, 25 February 2026
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	A '''comma pump''' is a JI or tempered chord progression whose starting and ending points differ by a [[comma]].		A '''comma pump''' is a JI or tempered chord progression whose starting and ending points differ by a [[comma]].

	There is some ambiguity in this term depending on whether the comma in question is tempered out (thus returning to the starting pitch) or not. If the comma is tempered out the chord progression ~~could~~ be called a '''comma loop'''.		There is some ambiguity in this term depending on whether the comma in question is tempered out (thus returning to the starting pitch) or not. If the comma is tempered out, the chord progression may be called a '''comma loop'''.

	Given a comma, a comma pump may be constructed by stacking root movements by basic intervals in the JI group in question to that comma. Reordering movements of a comma pump, or reversing the movements, creates another valid comma pump progression for that comma.		Given a comma, a comma pump may be constructed by stacking root movements by basic intervals in the JI group in question to that comma. Reordering movements of a comma pump, or reversing the movements, creates another valid comma pump progression for that comma.

2026-02-25T03:14:35Z

← Older revision		Revision as of 03:14, 25 February 2026
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	There is some ambiguity in this term depending on whether the comma in question is tempered out (thus returning to the starting pitch) or not. If the comma is tempered out the chord progression could be called a '''comma loop'''.		There is some ambiguity in this term depending on whether the comma in question is tempered out (thus returning to the starting pitch) or not. If the comma is tempered out the chord progression could be called a '''comma loop'''.

	Given a comma, a comma pump may be constructed by stacking root movements by basic intervals in the JI group in question to that comma. Reordering movements of a comma pump creates another valid comma pump progression for that comma.		Given a comma, a comma pump may be constructed by stacking root movements by basic intervals in the JI group in question to that comma. Reordering movements of a comma pump, or reversing the movements, creates another valid comma pump progression for that comma.

	== Examples ==		== Examples ==

2026-02-25T03:14:08Z

Examples

← Older revision		Revision as of 03:14, 25 February 2026
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	-> G Bb^ D G (Bb^ -> G: down 6/5)		-> G Bb^ D G (Bb^ -> G: down 6/5)
	-> C Ev G (G -> C: up 4/3)		-> C Ev G (G -> C: up 4/3)

			=== Slendric ===
			[[Slendric]] equates three 8/7's with one 3/2. Below, ^/v indicates alteration by 64/63.

			C G Bbv
			D^ A^ C (C -> D^: up 8/7)
			Fv Cv Ebvv (D^ -> E^^ = Fv: up 8/7)
			G D Fv (Fv -> G: up 8/7)
			C Bbv G (G -> C: down 3/2)

2026-02-24T23:04:25Z

Porcupine

← Older revision		Revision as of 23:04, 24 February 2026
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	=== Porcupine ===		=== Porcupine ===
	Here's a [[Porcupine]] (250/243) comma loop, which only returns to the starting pitch in Porcupine tunings (^/v = 81/80 alteration):		Here's a [[Porcupine]] (250/243) comma loop, which only returns to the starting pitch in Porcupine tunings (^/v = 81/80 alteration). Note that 250/243 is the interval between 81/80 and 25/24.

	C Ev G		C Ev G

2026-02-24T23:03:16Z

Meantone

← Older revision		Revision as of 23:03, 24 February 2026
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	-> CEGC (G -> C: up by 4/3)		-> CEGC (G -> C: up by 4/3)

	In JI and other non-Meantone tunings, attempting this comma pump results in the end point flatter by 81/80 relative to the starting point. In [[21edo]], since 81/80 is mapped to -1\21, this progression ''raises'' the pitch by 1\21.		In JI and other non-Meantone tunings, attempting this comma pump results in the end point being flatter by (possibly tempered) 81/80 relative to the starting point. In [[21edo]], since 81/80 is mapped to -1\21, this progression ''raises'' the pitch by 1\21.

	=== Porcupine ===		=== Porcupine ===

2026-02-24T23:02:40Z

Meantone

← Older revision		Revision as of 23:02, 24 February 2026
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	== Examples ==		== Examples ==
	=== Meantone ===		=== Meantone ===
	The I-vi-ii-V-I progression is a [[Meantone]] or [[81/80]] comma loop:		The I-vi-ii-V-I diatonic progression in Meantone diatonic is a [[Meantone]] or [[81/80]] comma loop:

	CEG		CEG