Editing Altered chord (section)

== Alt chord<!--[[Alt chord]] redirects directly here.--> ==
{{More citations needed section|date=November 2018}}
{{Image frame|content=<score sound="1"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' {
   \clef treble
   \time 4/4
   \key c \major
   \textLengthOn
   <g b f' aes ais des es>1
} }
</score>|width=300|caption=G<sup>7alt</sup> chord with {{music|flat}}5 and {{music|sharp}}5 as well as {{music|flat}}9 and {{music|sharp}}9}}
In jazz, the term ''altered chord'', notated generally as a root, followed by ''7alt'' (e.g. G<sup>7alt</sup>), refers to a [[dominant chord]] that fits entirely into the [[altered scale]] of the root. This means that the chord has the root, major third, minor seventh, and one or more altered tones, but does not have the natural fifth, ninth, eleventh, or thirteenth. An altered chord typically contains both an altered fifth and an altered ninth. To alter a tone is simply to raise or lower it by a [[semitone]].

Altered chords may include ''both'' a flattened and sharpened form of the altered fifth or ninth, e.g. A<sup>7({{music|b}}5{{music|b}}9{{music|#}}9)</sup>; however, it is more common to use only one such alteration per tone, e.g. B<sup>7({{music|#}}5{{music|b}}9)</sup> (which may also be spelled as B<sup>7({{music|b}}9{{music|b}}13)</sup>).

:<score lang="lilypond" sound="1"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' {
   \clef treble
   \time 4/4
   \key c \major
   \textLengthOn
   <g b f' aes des es>1_\markup { \concat { "G" \raise #1 \small { "7(♭5♯5♭9)" } } }
   <g b f' aes des>_\markup { \concat { "G" \raise #1 \small { "7(♭5♭9)" } } }
   <g b f' ais des>_\markup { \concat { "G" \raise #1 \small { "7(♭5♯9)" } } }
   <g b f' aes es'>_\markup { \concat { "G" \raise #1 \small { "7(♯5♭9)" } } }
   <g b f' ais es'>_\markup { \concat { "G" \raise #1 \small { "7(♯5♯9)" } } }
} }
</score>

The raised fifteenth is only used when the ninth in a chord is natural. It functions as a [[minor ninth]], creating a [[major seventh]] interval with the natural ninth, assuming that the chord is in root position. The notation of a raised fifteenth is a fairly modern addition to Western harmony, and they have been popularized by contemporary musicians like [[Jacob Collier]]. Natural [[fifteenth]]s are never notated as alterations or extensions, as they are [[enharmonic|enharmonically equivalent]] to the root. For example, a chord that includes a raised fifteenth could look something like G<sup>maj13({{music|#}}11{{music|#}}15)</sup>, or if it were written as a polychord, {{sfrac|A<sup>maj7</sup>|G<sup>maj7</sup>}}.

In practice, many [[fake book]]s do not specify all the alterations; the chord is typically just labelled as G<sup>7alt</sup>, and the alteration of ninths, elevenths, thirteenths, and fifteenths is left to the artistic discretion of the comping musician. The use of chords labeled G<sup>7alt</sup> can create challenges in jazz ensembles where more than one chordal instrument are playing chords (e.g., a large band with an electric guitar, piano, vibes, and/or a [[Hammond organ]]), because the guitarist might interpret a G<sup>7alt</sup> chord as containing a {{music|b}}9 and {{music|#}}11, whereas the organ player may interpret the same chord as containing a {{music|#}}9 and a {{music|b}}13, resulting in every tone from the altered scale at once, likely a far denser and more dissonant harmonic cluster than the composer intended. To deal with this issue, bands with more than one chordal instrument may work out the alt chord [[Voicing (music)|voicings]] beforehand or alternate playing of choruses.

The choice of [[Inverted chord|inversion]], or the omission of certain tones within the chord (e.g. omitting the root, common in jazz harmony and chord voicings), 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 (music)|modulation]], and [[voice leading]].

{{Image frame|content=<score sound="1">
{
\override Score.TimeSignature #'stencil = ##f
\relative c' {
  \clef treble \time 7/4
  c4 des es fes ges aes bes c2 }
}
</score>|width=300|caption=The [[altered scale]] on C}}

The altered chord's harmony is built on the [[altered scale]] (C, D{{music|b}}, E{{music|b}}, F{{music|b}}, G{{music|b}}, A{{music|b}}, B{{music|b}}, C), which includes all the alterations shown in the chord elements above:<ref>Brown, Buck; and Dziuba, Mark (2012). ''The Ultimate Guitar Chord & Scale Bible'', p. 197. Alfred Music. {{ISBN|9781470622626}} "In a dominant 7 context, this scale contains the root, 3rd, and {{music|b}}7 of the dominant chord and includes all of the available tensions: {{music|b}}9, {{music|#}}9, {{music|#}}11, and {{music|b}}13.</ref>

* root
*{{music|b}}9 (= {{music|b}}2)
*{{music|#}}9 (= {{music|#}}2 or {{music|b}}3)
* major third (enharmonically, as {{music|b}}4)
*{{music|#}}11 (= {{music|#}}4 or {{music|b}}5)
*{{music|b}}13 (= {{music|#}}5)
*{{music|b}}7

{{Image frame|content=<score sound="1"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' {
   \clef treble
   \time 4/4
   \key c \major
   \textLengthOn
   <c e g bes d fis a>1_\markup { \concat { "C" \raise #1 \small { "7" } } }
  <fis ais cis e gis bis dis>_\markup { \concat { "F♯" \raise #1 \small { "7" } } }
  <c e gis c dis f ais>_\markup { \concat { "C" \raise #1 \small { "7(♯5♯9)" } } }
} }
</score>|width=300|caption=Tritone substitution for C<sup>7</sup> (F{{music|sharp}}<sup>7</sup>) and altered chord (C<sup>7({{music|#}}5{{music|#}}9)</sup>) as "nearly identical"<ref name="Coker 81">[[Jerry Coker|Coker, Jerry]] (1997). ''Elements of the Jazz Language for the Developing Improvisor'', p. 81. {{ISBN|1-57623-875-X}}.</ref>}}

Because they do not have natural fifths, altered dominant (7alt) chords support [[tritone substitution]] ({{music|b}}5 substitution). Thus, the 7alt chord on a given root can be substituted with the 13{{music|#}}11 chord on the root a [[tritone]] away (e.g., G<sup>7alt</sup> is the same as D{{music|b}}<sup>13{{music|#}}11</sup>).

:<score sound="1"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' {
   \clef treble
   \time 4/4
   \key c \major
   \textLengthOn
   <des f aes ces es g bes>1_\markup { \concat { "D♭" \raise #1 \small { "13(♯11)" } } }
} }
</score>