Comma pump: Difference between revisions
From Xenharmonic Reference
Created page with "A '''comma pump''' is a chord progression whose starting and ending points differ by a comma in JI. The I-vi-ii-V-I progression is a Meantone or 81/80 comma pump: CEG -> ACEA -> DFA -> GDGB -> CEGC In non-Meantone tunings, attempting this comma pump results in the end point flatter by 81/80 relative to the starting point. There is some ambiguity in this term depending on whether the comma in question is tempered out or not. If the comma is tempered out the chord..." |
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The I-vi-ii-V-I progression is a [[Meantone]] or 81/80 comma pump: | The I-vi-ii-V-I progression is a [[Meantone]] or 81/80 comma pump: | ||
CEG -> ACEA -> DFA -> GDGB -> CEGC | CEG | ||
-> ACEA (down by 6/5) | |||
-> DFA (up by 4/3) | |||
-> GDGB (down by 3/2) | |||
-> CEGC (up by 4/3) | |||
In non-Meantone tunings, attempting this comma pump results in the end point flatter by 81/80 relative to the starting point. | In non-Meantone tunings, attempting this comma pump results in the end point flatter by 81/80 relative to the starting point. | ||
There is some ambiguity in this term depending on whether the comma in question is tempered out or not. If the comma is tempered out the chord progression could be called a '''comma cycle'''. | There is some ambiguity in this term depending on whether the comma in question is tempered out or not. If the comma is tempered out the chord progression could be called a '''comma cycle'''. | ||
Revision as of 20:35, 24 February 2026
A comma pump is a chord progression whose starting and ending points differ by a comma in JI.
The I-vi-ii-V-I progression is a Meantone or 81/80 comma pump:
CEG -> ACEA (down by 6/5) -> DFA (up by 4/3) -> GDGB (down by 3/2) -> CEGC (up by 4/3)
In non-Meantone tunings, attempting this comma pump results in the end point flatter by 81/80 relative to the starting point.
There is some ambiguity in this term depending on whether the comma in question is tempered out or not. If the comma is tempered out the chord progression could be called a comma cycle.
