Editing Altered chord (section)

{{Short description|Musical terminology}}
{{For|similar terms|Alteration (disambiguation)|Modification (disambiguation){{!}}Modification}}
{{Distinguish|Leading tone}}
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\relative c'' {
   \clef treble
   \time 4/4
   \key c \major
   \textLengthOn
   <g b d>1^\markup { \tiny "Unaltered V"} <gis b des>^\markup { \tiny "Altered V"} \bar "||"
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</score>|width=210|caption=An altered dominant chord in C major<ref name="Erickson"/>}}

An '''altered chord''' is a [[chord (music)|chord]] that replaces one or more notes from the [[diatonic scale]] with a neighboring pitch from the [[chromatic scale]]. By the broadest definition, any chord with a non-diatonic chord tone is an altered chord. The simplest example of altered chords is the use of [[borrowed chord]]s, chords borrowed from the [[parallel key]], and the most common is the use of [[secondary dominant]]s. As Alfred Blatter explains, "An altered chord occurs when one of the standard, functional chords is given another quality by the modification of one or more components of the chord."<ref>Blatter, Alfred (2007). ''Revisiting Music Theory: A Guide to the Practice'', p. 186. {{ISBN|0-415-97440-2}}.</ref>

For example, altered notes may be used as [[leading tone]]s to emphasize their diatonic neighbors. Contrast this with [[Extended chord|chord extensions]]:

{{blockquote|Whereas chord extension generally involves adding notes that are logically implied, chord alteration involves changing some of the typical notes. This is usually done on [[dominant chord]]s, and the four alterations that are commonly used are the {{music|b}}5, {{music|#}}5, {{music|b}}9 and {{music|#}}9. Using one (or more) of these notes in a resolving dominant chord greatly increases the bite in the chord and therefore the power of the [[resolution (music)|resolution]].<ref>[[Noah Baerman|Baerman, Noah]] (1998). ''Complete Jazz Keyboard Method: Intermediate Jazz Keyboard'', p. 70. {{ISBN|0-88284-911-5}}.</ref>|sign=|source=}}

In [[jazz harmony]], chromatic alteration is either the addition of notes not in the scale or expansion of a [chord] progression by adding extra non-diatonic chords.<ref name="Arkin">Arkin, Eddie (2004). ''Creative Chord Substitution for Jazz Guitar'', p. 42. {{ISBN|0-7579-2301-1}}.</ref> For example, "A C major scale with an added D{{music|sharp}} note, for instance, is a chromatically altered scale" while, "one bar of C<sup>maj7</sup> moving to F<sup>maj7</sup> in the next bar can be chromatically altered by adding the ii and V of F<sup>maj7</sup> on the second two beats of bar" one. Techniques include the [[ii–V–I turnaround]], as well as movement by half-step or minor third.<ref name="Arkin 43">Arkin (2004), p. 43.</ref>

:[[File:Altered_chord_progression_jazz.png|frameless|400x400px]]

The five most common types of altered dominants are: V{{music|+}}, V{{sup|7}}<sup>{{music|sharp}}5</sup> (both with raised fifths), V{{sup|{{music|b}}5}}, V{{sup|7}}<sup>{{music|flat}}5</sup> (both with lowered fifths), and V{{music|halfdim}}{{sup|7}} (with lowered fifth and third, the latter enharmonic to a raised ninth).<ref>Benward and Saker (2009), p. 193.</ref>