Altered chord: Difference between revisions
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==Jazz== |
==Jazz== |
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In [[jazz]] and [[jazz harmony]], an '''altered chord''' is a [[dominant chord|dominant]] [[ninth]] [[chord (music)|chord]] that has the 5th and the 9th raised and/or lowered by a single [[semi-tone]] {{Fact|date=July 2008}}. An altered chord may contain any of the following : |
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In [[jazz]] and [[jazz harmony]], the term '''altered chord''' refers to a [[dominant chord|dominant]] [[chord (music)|chord]] "in which neither the fifth nor the ninth appears unaltered" and which thus "contains b5 &/or #5, and b9 &/or #9".<ref>Sher (ed.), ''The New Real Book Volume Two'', Sher Music Co., 1991, ISBN 0-9614701-7-8</ref> – in other words, where the 5th and the 9th are raised or lowered by a single [[semi-tone]], or omitted. This chord is notated as an "alt chord" (e.g. G7alt {{Audio|G7alt chord.mid|Play}}). |
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Altered chords are thus constructed using the following notes, some of which may be omitted: |
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* root |
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* b5 and/or #5 |
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* b9 and/or #9 |
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The chord may thus include ''both'' a flatted and sharped form of the altered fifth or ninth, e.g. G7b5#5b9; however, it is more common to use only one such alteration per tone, e.g. G7b5b9, G7b5#9, G7#5b9, or G7#5#9. |
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The choice of [[inversion (music)|inversion]], or the omission of certain tones within the chord (e.g. omitting the root, common in guitar harmony), can lead to many different possible colorings, substitutions, and [[enharmonic|enharmonic equivalents]]. Altered chords are ambiguous harmonically, and may play a variety of roles, depending on such factors as [[voicing (music)|voicing]], [[modulation (music)|modulation]], and [[voice leading]]. |
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The altered chord's harmony is built off the [[altered scale]], which includes all the alterations shown in the chord elements above: |
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* root |
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* b9 |
* b9 |
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* #9 |
* #9 |
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* #11 (=b5) |
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* b13 (=#5) |
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* b7 |
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They may be in any combination. It is more common to have one of each, for example an altered 5th and an altered 9th rather than both being altered 5ths (or altered 9ths). Note that the seventh (b7) is already present in the dominant chord. |
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{{Audio|Altered chord on C.mid|Play altered chord with flat 5th, 7th, and 9th}} |
{{Audio|Altered chord on C.mid|Play altered chord with flat 5th, 7th, and 9th}} |
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Altered chords are commonly substituted for regular dominant V chords in [[II-V-I|ii-V-I]] progressions, most commonly in minor harmony leading to an i7 (minor 7th) chord. |
Altered chords are commonly substituted for regular dominant V chords in [[II-V-I|ii-V-I]] progressions, most commonly in minor harmony leading to an i7 (root minor 7th) chord. |
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| ⚫ | More generally in jazz, the terms '''altered chord''' and '''altered tone'' also refer to the family of chords that involve b9 and b5 voicing, as well as to certain other chords with related ambiguous harmony. Thus the "b9 chord" (e.g. G7b9) is used in the context of a dominant resolution to a major tonic, which is typically voiced with a natural 13 rather than the b13 of the alt chord. When voiced with a natural 13, jazz musicians typically play the half-step/whole-step [[diminished scale]] over the b9 chord (e.g. G, Ab, Bb, B, C#, D, E, F). |
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==Sources== |
==Sources== |
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{{reflist}} |
{{reflist}} |
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Revision as of 22:22, 7 September 2008
 | This article needs additional citations for verification. (July 2008) |
In music, an altered chord, an example of alteration, is a chord with one or more diatonic notes replaced by, or altered to, a neighboring pitch in the chromatic scale. For example the following progression [1]:
uses an altered IV chord and is an alteration of [1]:
The Ab serves as a leading tone to G.
Jazz
In jazz and jazz harmony, the term altered chord refers to a dominant chord "in which neither the fifth nor the ninth appears unaltered" and which thus "contains b5 &/or #5, and b9 &/or #9".[2] – in other words, where the 5th and the 9th are raised or lowered by a single semi-tone, or omitted. This chord is notated as an "alt chord" (e.g. G7alt ).
Altered chords are thus constructed using the following notes, some of which may be omitted:
- root
- 3
- b5 and/or #5
- b7
- b9 and/or #9
The chord may thus include both a flatted and sharped form of the altered fifth or ninth, e.g. G7b5#5b9; however, it is more common to use only one such alteration per tone, e.g. G7b5b9, G7b5#9, G7#5b9, or G7#5#9.
The choice of inversion, or the omission of certain tones within the chord (e.g. omitting the root, common in guitar harmony), can lead to many different possible colorings, substitutions, and enharmonic equivalents. Altered chords are ambiguous harmonically, and may play a variety of roles, depending on such factors as voicing, modulation, and voice leading.
The altered chord's harmony is built off the altered scale, which includes all the alterations shown in the chord elements above:
- root
- b9
- #9
- #11 (=b5)
- b13 (=#5)
- b7
The "alt chord" can be analyzed as a kind of tritone substitution (b5 substitution). Thus the alt chord on a given root is the same as the 7#11 chord on the root a tritone away (e.g., G7alt is the same as Db7#11 ).
Altered chords are commonly substituted for regular dominant V chords in ii-V-I progressions, most commonly in minor harmony leading to an i7 (root minor 7th) chord.
More generally in jazz, the terms altered chord' and altered tone also refer to the family of chords that involve b9 and b5 voicing, as well as to certain other chords with related ambiguous harmony. Thus the "b9 chord" (e.g. G7b9) is used in the context of a dominant resolution to a major tonic, which is typically voiced with a natural 13 rather than the b13 of the alt chord. When voiced with a natural 13, jazz musicians typically play the half-step/whole-step diminished scale over the b9 chord (e.g. G, Ab, Bb, B, C#, D, E, F).
