Editing Chord progression

{{Use dmy dates|date=April 2021}}
{{short description|Succession of musical chords}}
{{seealso|List of chord progressions}}
{{Image frame|content=<score sound="1">
    {
      \new PianoStaff <<
        \new Staff <<
            \new Voice \relative c'' {
                \stemUp \clef treble \key c \major \time 4/4
                c2 b c1
                }
            \new Voice \relative c' {
                \stemDown
                f2 d e1
                }
            >>
        \new Staff <<
            \new Voice \relative c' {
                \stemUp \clef bass \key c \major \time 4/4
                a2 g g1
                }
            \new Voice \relative c {
                \stemDown
                f,2_\markup { \concat { \translate #'(-4 . 0) { "C:  IV" \hspace #2.2 "V" \hspace #5.3 "I" } } }
                g c1 \bar "||"
                }
            >>
    >> }
</score>|width=300|caption=A IV–V–I progression in the key of C major. The chords shown are F major, G major, and C major.}}In a [[musical composition]], a '''chord progression''' or '''harmonic progression''' (informally '''chord changes''', used as a [[plural]], or simply '''changes''') is a succession of [[chord (music)|chord]]s. Chord progressions are the foundation of [[harmony]] in Western musical tradition from the [[Common practice period|common practice era]] of [[Classical music]] to the 21st century. Chord progressions are the foundation of [[popular music]] styles (e.g., [[pop music]], [[rock music]]), [[traditional music]], as well as genres such as [[blues]] and [[jazz]]. In these genres, chord progressions are the defining feature on which [[melody]] and [[rhythm]] are built.

In tonal music, chord progressions have the function of either establishing or otherwise contradicting a [[tonality]], the technical name for what is commonly understood as the "[[Key (music)|key]]" of a song or piece. Chord progressions, such as the extremely common chord progression I-V-vi-IV, are usually expressed by [[Roman numeral analysis|Roman numerals]] in Classical music theory. In many styles of popular and traditional music, chord progressions are expressed using the name and "[[Chord quality|quality]]" of the chords. For example, the previously mentioned chord progression, in the key of E{{music|flat}} major, would be written as E{{music|flat}} major–B{{music|flat}} major–C minor–A{{music|flat}} major in a fake book or [[lead sheet]]. In the first chord, E{{music|flat}} major, the "E{{music|flat}}" indicates that the chord is built on the [[Root (chord)|root note]] "E{{music|b}}" and the word "major" indicates that a [[major chord]] is built on this "E{{music|b}}" note.

In rock and blues, musicians also often refer to chord progressions using [[Roman numerals]], as this facilitates transposing a song to a new key. For example, rock and blues musicians often think of the [[Twelve-bar blues|12-bar blues]] as consisting of I, IV, and V chords. Thus, a simple version of the 12-bar blues might be expressed as I–I–I–I, IV–IV–I–I, V–IV–I–I. By thinking of this blues progression in Roman numerals, a [[backup band]] or [[rhythm section]] could be instructed by a [[bandleader]] to play the chord progression in any key. For example, if the bandleader asked the band to play this chord progression in the key of B{{music|b}} major, the chords would be B{{music|b}}-B{{music|b}}-B{{music|b}}-B{{music|b}}, E{{music|b}}-E{{music|b}}-B{{music|b}}-B{{music|b}}, F-E{{music|b}}-B{{music|b}}-B{{music|b}}.

The complexity of a chord progression varies from genre to genre and over different historical periods. Some pop and rock songs from the 1980s to the 2010s have fairly simple chord progressions. [[Funk]] emphasizes the [[Groove (music)|groove]] and rhythm as the key element, so entire funk songs may be based on one chord. Some [[jazz-funk]] songs are based on a two-, three-, or four-chord [[Vamp (music)|vamp]]. Some [[punk rock|punk]] and [[hardcore punk]] songs use only a few chords. On the other hand, [[bebop]] jazz songs may have [[32 bar song form|32-bar song form]]s with one or two chord changes every bar.

==Basic theory==
[[File:Chord progression.png|thumb|338px|The key note, or [[Tonic (music)|tonic]], of a piece of music is called note number one, the first step of (here), the ascending scale iii–IV–V. Chords built on several [[scale degree]]s are numbered likewise. Thus the chord progression E minor–F–G can be described as three–four–five, (or iii–IV–V).]]

A chord may be built upon any note of a [[musical scale]]. Therefore, a seven-note [[diatonic scale]] allows seven basic [[Diatonic chord|diatonic triads]], each degree of the scale becoming the [[Root (music)|root]] of its own chord.<ref>[[George Whitefield Chadwick]], ''Harmony: A Course of Study'', 72nd ed. B. F.Wood Music, 1922, Introduction p. xv</ref> A chord built upon the note E is an E chord of some [[Chord quality|type]] (major, minor, diminished, etc.) Chords in a progression may also have more than three notes, such as in the case of a [[seventh chord]] (V<sup>7</sup> is particularly common, as it resolves to I) or an [[extended chord]]. The harmonic [[Function (music)|function]] of any particular chord depends on the context of the particular chord progression in which it is found.<ref name="Schoenberg">[[Arnold Schoenberg|Schoenberg, Arnold]]. ''Structural Functions of Harmony'', Norton, 1954, p. 1.</ref>

=== Diatonic and chromatic chords ===
The diatonic harmonization of any [[major scale]] results in three [[Major chord|major triads]], which are based on the first, fourth, and fifth [[scale degree]]s. The triads are referred to as the [[tonic chord]] (in [[Roman numeral analysis]], symbolized by "I"), the [[subdominant chord]] (IV), and the [[dominant chord]], (V), respectively.<ref>Chadwick, 1922, p.1</ref> These three triads include, and therefore can [[harmonization|harmonize]], every note of that scale. Many simple [[traditional music]], [[folk music]] and [[rock and roll]] songs use only these three chord types (e.g. [[The Troggs]]' "[[Wild Thing (The Troggs song)|Wild Thing]]", which uses I, IV and V chords).

The same major scale also has three [[minor chord]]s, the [[Supertonic|supertonic chord]] (ii), [[mediant chord]] (iii), and [[submediant chord]] (vi), respectively. These chords stand in the same relationship to one another (in the [[relative minor key]]) as do the three major chords, so that they may be viewed as the first (i), fourth (iv) and fifth (v) degrees of the relative minor key. For example, the relative minor of C major is A minor, and in the key of A minor, the i, iv and v chords are A minor, D minor and E minor. In practice, in a minor key, the [[Third (chord)|third]] of the dominant chord is often raised by one semitone to form a major chord (or a [[dominant seventh chord]] if the [[Seventh (chord)|seventh]] is added).

In addition, the seventh degree of the major scale (i.e. the [[Leading-tone|leading tone]]) forms a [[Diminished triad|diminished chord]] (vii{{music|dim}}).<ref>C. H. Kitson, ''Elementary Harmony, Part One'', Oxford University Press, 1920, chapters 3–4.</ref>

A chord may also have [[Diatonic and chromatic|chromatic]] notes, that is, notes outside of the diatonic scale. Perhaps the most basic chromatic [[Altered chord|alteration]] in simple folk songs is the raised fourth degree ({{music|sharp}}{{music|scale|4}}) that results when the [[Third (chord)|third]] of the ii chord is raised one [[semitone]]. Such a chord typically functions as the [[secondary dominant]] of the V chord (V/V). In some instances, chromatic notes are introduced to [[Modulation (music)|modulate]] to a new key. This in turn may lead to a [[Resolution (music)|resolution]] back to the original key later on, so that the entire sequence of chords helps create an extended [[musical form]] and a sense of movement.

=== Progressions ===
Although there are many possible progressions, in practice, progressions are often limited to a few bars' lengths and certain progressions are favored above others. There is also a certain amount of fashion in which a chord progression is defined (e.g., the [[Twelve-bar blues|12-bar blues]] progression) and may even help in defining an entire [[Music genre|genre]].{{citation needed | date=June 2017}}

In western [[Classical music|classical]] notation, chords are numbered with Roman numerals. Other types of [[chord notation]] have been devised, from [[figured bass]] to the [[chord chart]]. These usually allow or even require a certain amount of [[Improvisation (music)|improvisation]].

== Common progressions ==

===Simple progressions===
[[Diatonic]] scales such as the [[major and minor]] scales lend themselves particularly well to the construction of common chords because they contain many [[perfect fifth]]s. Such scales predominate in those regions where harmony is an essential part of music, as, for example, in the [[common practice period]] of western classical music. In considering [[Arabic music|Arab]] and [[Music of India|Indian]] music, where diatonic scales are used, there are also available a number of non-diatonic scales, the music has no chord changes, remaining always upon the key-chord, an attribute which has also been observed in [[hard rock]], [[hip hop]],<ref>{{cite journal|jstor=10.1525/mp.2002.19.3.285|title=Black Atlantic Rhythm: Its Computational and Transcultural Foundations|author=Jeff Pressing|journal=Music Perception|volume=19|date=2002|issue=3|pages=285–310|publisher=[[University of California Press]]|doi=10.1525/mp.2002.19.3.285}}</ref> [[funk]], [[disco]],<ref>{{cite web|url=http://www.yosemiteuhsd.com/finearts/rock/15_funk_disco.pdf |title=Chapter 15---Funk and Disco |access-date=6 May 2011 |url-status=dead |archive-url=https://web.archive.org/web/20110719204120/http://www.yosemiteuhsd.com/finearts/rock/15_funk_disco.pdf |archive-date=19 July 2011 }}</ref> [[jazz]], etc.

Alternation between two chords may be thought of as the most basic chord progression. Many well-known pieces are built harmonically upon the mere repetition of two chords of the same scale.<ref name="Schoenberg" /> For example, many of the more straightforward melodies in classical music consist entirely or mostly of alternation between the tonic (I) and the dominant (V, sometimes with an [[Dominant seventh chord|added seventh]]), as do popular songs such as "[[Achy Breaky Heart]]".<ref>{{Cite web|url=https://www.musicnotes.com/sheetmusic/mtd.asp?ppn=MN0042636|title=Achy Breaky Heart|last1=Von|first1=Tress, Don|last2=Ray|first2=Cyrus, Billy|date=26 August 2002|website=Musicnotes.com|access-date=1 August 2019}}</ref> [[The Isley Brothers]]' "[[Shout (Isley Brothers song)|Shout]]" uses I–vi throughout.<ref>{{cite web|url=http://www.musicnotes.com/sheetmusic/mtdVPE.asp?ppn=MN0063604 |title=The Isley Brothers "Shout" Sheet Music in F Major (transposable)|website=Musicnotes.com |date=23 August 2010 |access-date=17 July 2016}}</ref>

===Three-chord progressions===
{{See also|Three-chord song}}
Three-chord progressions are more common since a melody may then dwell on any note of the scale. They are often presented as successions of four chords (as shown below), in order to produce a binary [[harmonic rhythm]], but then two of the four chords are the same.

* {{nowrap|I – IV – V – V}}
* {{nowrap|I – I – IV – V}}
* {{nowrap|I – IV – I – V}}
* {{nowrap|I – IV – V – IV}}

Often the chords may be selected to [[Harmonization|fit a pre-conceived melody]], but just as often it is the progression itself that gives rise to the melody.

Similar progressions abound in [[African popular music]]. They may be varied by the addition of [[Seventh chord|sevenths]] (or other [[scale degrees]]) to any chord or by substitution of the [[relative minor]] of the IV chord to give, for example, I–ii–V. This sequence, using the [[Supertonic chord|ii chord]], is also used [[cadence (music)|cadentially]] in a common chord progression of [[jazz harmony]], the so-called [[ii–V–I progression|ii–V–I turnaround]].

Three-chord progressions provide the harmonic foundation of much African and American popular music, and they occur sectionally in many pieces of classical music (such as the opening bars of [[Beethoven]]'s [[Pastoral Symphony|''Pastoral'' Symphony]]<ref>{{Cite web|url=https://guitaralliance.com/2013/01/chord-progressions/|title=Chord Progressions|website=guitaralliance.com|access-date=1 February 2019}}</ref>).

Where such a simple sequence does not represent the entire harmonic structure of a piece, it may readily be extended for greater variety. Frequently, an opening [[Phrase (music)|phrase]] has the progression I–IV–V–V, which ends on an [[Resolution (music)|unresolved]] [[Dominant (music)|dominant]], may be "[[Period (music)|answered]]" by a similar phrase that resolves back onto the [[tonic chord]], giving a structure of double the length:
:{| class="wikitable" style="text-align:center; width:110px;"

| width="25%" |I
| width="25%" |IV
| width="25%" |V
| width="25%" |V
|-
|I
|IV
|V
|I
|}

Additionally, such a passage may be alternated with a different progression to give a simple [[Binary form|binary]] or [[ternary form]] such as that of the popular [[thirty-two-bar form|32-bar form]] (see [[musical form]]).

===Blues changes===
[[Image:Serenade Blues 1.jpg|thumb|right|210px|Blues progressions influenced a great deal of 20th century American popular music]]
The [[twelve bar blues|12-bar blues]] and its many variants use an elongated, three-line form of the I–IV–V progression that has also generated countless hit records, including the most significant output of [[rock and roll]]ers such as [[Chuck Berry]] and [[Little Richard]]. In its most elementary form (and there are many variants), the chord progression is
:{| class="wikitable" style="text-align:center; width:110px;"

| width="25%" |I
| width="25%" |I
| width="25%" |I
| width="25%" |I
|-
|IV
|IV
|I
|I
|-
|V
|IV
|I
|I
|}
Blues progressions have also been subjected to densely chromatic elaboration, as in the [[Bird blues]].

Steedman (1984) proposed that a set of recursive [[rewrite rule]]s generate all [[well-formed scale|well-formed]] [[Transformation (music)|transformation]]s of jazz, both basic blues chord changes and slightly modified sequences (such as the "[[rhythm changes]]"). Important transformations include:

* replacement of (or addition to) a chord with its dominant, subdominant or the [[tritone substitution]].
* use of chromatic passing chords.
* extensively applying the [[ii–V–I progression|ii–V–I turnaround]].
* chord alterations such as minor chords, diminished sevenths, etc.<ref>Steedman, M. J., "A Generative Grammar for Jazz Chord Sequences", ''Music Perception'' '''2''' (1) (1984) 52–77.</ref>

===1950s progression===
{{Image frame|content=<score sound="1"> {
\relative c' {
   \clef treble 
   \time 4/4
   \key c \major
   <c e g>1_\markup { \concat { \translate #'(-3.5 . 0) { "C:   I" \hspace #7 "vi" \hspace #6 "IV" \hspace #6 "V" \hspace #7 "I" } } }
   <a c e a> <f c' f a> <g b d g> <c e g> \bar "||"
} }
</score>|width=345|caption=A 50s progression in C}}
Another common way of extending the I–IV–V progression is by adding the chord of the sixth scale degree, giving the sequence I–vi–IV–V or [[I−vi−ii−V|I–vi–ii–V]], sometimes called the [[50s progression]] or doo-wop progression.

This progression had been in use from the earliest days of classical music and then generated popular hits such as [[Rodgers and Hart]]'s "[[Blue Moon (1934 song)|Blue Moon]]" (1934)<ref>{{Cite web|url=http://www.jazzstandards.com/compositions-0/bluemoon.MusicandLyricsAnalysis.htm|title=Jazz Standards Songs and Instrumentals (Blue Moon)|website=www.jazzstandards.com|access-date=22 May 2019|archive-date=27 September 2018|archive-url=https://web.archive.org/web/20180927041932/http://www.jazzstandards.com/compositions-0/bluemoon.MusicandLyricsAnalysis.htm|url-status=dead}}</ref> and [[Hoagy Carmichael]]'s "[[Heart and Soul (1938 song)|Heart and Soul]]" (1938).<ref>"[https://archive.today/20130111064707/http://www.musicnotes.com/sheetmusic/mtdFPE.asp?ppn=MN0096746& Heart and Soul (1938)] ", ''MusicNotes.com''. Chords marked. {{subscription required|date=July 2016}}</ref>

Taken up into the pop mainstream, it continued to be used sectionally, as in the last part of The Beatles' "[[Happiness is a warm gun|Happiness Is a Warm Gun]]".<ref>{{cite web|url=http://www.beatlesbible.com/songs/happiness-is-a-warm-gun/ |title=Happiness Is A Warm Gun |date=15 March 2008 |publisher=The Beatles Bible |access-date=17 July 2016}}</ref>

{{Clear}}

===Circle progressions===
{{Image frame|content=<score sound="1">
    {
      \new PianoStaff <<
        \new Staff <<
            \new Voice \relative c' {
                \clef treble \time 4/4
                \stemUp e2 f d e c d b c
                }
            \new Voice \relative c' {
                \stemDown c2 c b b a a g g
                }
            >>
        \new Staff <<
            \new Voice \relative c' {
                \clef bass \time 4/4
                \stemUp g2 a f g e f d e 
                }
            \new Voice \relative c {
                \stemDown c_\markup { \concat { \translate #'(-4 . 0) { "C:   I" \hspace #2.8 "IV" \hspace #3 "vii" \raise #1 \small "o" \hspace #1.5 "iii" \hspace #3.2 "vi" \hspace #2.5 "ii" \hspace #3.8 "V" \hspace #3 "I" } } }
                f, b e, a d, g c,
                }
            >>
    >> }
</score>|width=340|caption=A [[circle progression]] in C major}}{{Image frame|content=<score sound="1"> {
\relative c' {
   \clef treble 
   \time 4/4
   \key c \major
   <e gis b d>1_\markup { \concat { \translate #'(-3.5 . 0) { "C:  III" \raise #1 \small "7" \hspace #5 "VI" \raise #1 \small "7" \hspace #5.5 "II" \raise #1 \small "7" \hspace #5.5 "V" \raise #1 \small "7" } } }
   <a, e' g! cis> <d fis a c!> < g, d' f! b> \bar "||"
} }
</score>|width=310|caption=The [[ragtime progression]] (E<sup>7</sup>–A<sup>7</sup>–D<sup>7</sup>–G<sup>7</sup>) often appears in the [[bridge (music)|bridge]] of [[jazz standard]]s.<ref>Boyd, Bill (1997). ''Jazz Chord Progressions'', p. 56. {{ISBN|0-7935-7038-7}}.</ref> The III<sup>7</sup>–VI<sup>7</sup>–II<sup>7</sup>–V<sup>7</sup> (or V<sup>7</sup>/V/V/V–V<sup>7</sup>/V/V–V<sup>7</sup>/V–V<sup>7</sup>) leads back to C major (I) but is itself indefinite in key.}}Introducing the ii chord into these progressions emphasises their appeal as constituting elementary forms of [[circle progression]]. These, named for the [[circle of fifths]], consist of "adjacent [[Root (chord)|roots]] in ascending fourth or descending fifth relationship"&mdash;for instance, the sequence vi–ii–V–I ascends with each successive chord to one a fourth above the previous. Such a motion, based upon close harmonic relations, offers "undoubtedly the most common and the strongest of all harmonic progressions".<ref name="B&S">{{cite book|last1=Benward|first1=Bruce|last2=Saker|first2=Marilyn|year=2003|title=Music: In Theory and Practice|volume=I|page=178|publisher=McGraw-Hill |edition=7th|isbn=978-0-07-294262-0}}</ref>

Short cyclical progressions may be derived by selecting a sequence of chords from the series completing a circle from the tonic through all seven diatonic chords:<ref name="B&S"/><blockquote>I–IV–vii<sup>o</sup>–iii–vi–ii–V–I</blockquote>This type of progression was much used by classical composers, who introduced increasingly subtle inflections. Particularly, substitution of major for minor chords giving, for example, I–VI–II–V allowed a more sophisticated [[chromaticism]] as well as the possibility of [[modulation (music)|modulation]]. These harmonic conventions were taken up by American popular entertainers, giving rise to many variations on those harmonic staples of early [[jazz]] that have been dubbed the [[ragtime progression]] and the [[stomp progression]]. All such progressions may be found used sectionally, as for example in the much-used "[[rhythm changes]]" of [[George Gershwin]]'s "[[I Got Rhythm]]".

==Harmonizing the scale==
{{More citations needed|date=June 2019}}
As well as the cyclical underpinning of chords, the ear tends to respond well to a linear thread; chords following the scale upwards or downwards. These are often referred to as step progressions<ref>{{Cite web|title=12. Basic Two-Voice Interval Progressions|url=https://milnepublishing.geneseo.edu/fundamentals-function-form/chapter/12-basic-two-voice-interval-progressions/|access-date=18 September 2020|publisher=Milne Library|language=en-US|last1=Mount |first1=Andre }}</ref> because they follow the steps of the scale, making the scale itself a [[bassline]]. In the 17th century, descending bass lines found favour for [[Division (music)|"division]]s on the ground", so that [[Pachelbel's canon]] contains very similar harmonizations of the descending major scale.

At its simplest, this descending sequence may simply introduce an extra chord, either III or V, into the I–vi–IV–V type of sequence described above. This chord allows the harmonization of the [[Subtonic|seventh degree]], and so of the bass line I–VII–VI....

The finale measures of the first movement of [[Maurice Ravel|Ravel]]'s [[Piano Concerto in G (Ravel)|Piano Concerto in G]] feature the harmonization of a descending hybrid scale ([[Neapolitan scale|phrygo-major]]). In this special case, Ravel used a parallel series of major triads (G F{{music|sharp}} E D C B{{music|flat}} A{{music|flat}} G).

==Minor and modal progressions==
{{More citations needed|date=June 2019}}
{{Image frame|content=<score sound="1"> {
\relative c'' {
   \clef treble 
   \time 4/4
   \key a \minor
   <a c e>1_\markup { \concat { \translate #'(-3.5 . 0) { "a:   i" \hspace #6.5 "VII" \hspace #5.5 "VI" \hspace #6 "V" \raise #1 \small "7" \hspace #6 "i" } } }
   <g b d> <f a c> <e gis b \parenthesize d> <a c e> \bar "||"
} }
</score>|width=345|caption=A typical [[Andalusian cadence]] ''por arriba'' (i.e. in A&nbsp;minor). G is the [[subtonic]] and G{{sup|{{music|#}}}} is the [[leading tone]].}} Similar strategies to all the above, work equally well in [[Minor scale|minor modes]]: there have been one-, two-, and three-minor-chord songs, [[Twelve-bar blues#Minor blues|minor blues]]. A notable example of a descending minor chord progression is the four-chord [[Andalusian cadence]], i–VII–VI–V.

Folk and blues tunes frequently use the [[Mixolydian]] scale, which has a flat seventh degree, altering the position of the three major chords to I–{{sup|{{music|b}}}}VII–IV. For example, if the major scale of C, which gives the three chords C, F and G on the first, fourth and fifth degrees, is played with G as the tonic, then the same chords will now appear on the first, fourth, and seventh degrees. A common chord progression with these chords is I-{{music|b}}VII–IV-I, which also can be played as I-I-{{music|b}}VII–IV or {{music|b}}VII–IV-I-I.

The minor-third step from a minor key up to the [[relative major]] encouraged ascending scale progressions, particularly based on an ascending [[pentatonic scale]]. Typical of the type is the sequence i–III–IV (or iv)–VI.

According to Tom Sutcliffe:<ref name="sutcliffe">{{cite book |last=Sutcliffe |first=Tom |chapter=Appendix&nbsp;A (Pt.&nbsp;4) |title=Pop and Rock Music Modal Blues Progressions |series=Syntactic Structures in Music |url=http://www.harmony.org.uk/book/pop_and_rock_music_blues_modal_progressions.htm |access-date=22 July 2008 }}</ref>

{{quote |... during 1960s some pop groups started to experiment with modal chord progressions as an alternative way of harmonizing blues melodies. ... This created a new system of harmony that has influenced subsequent popular music.}}

This came about partly from the similarity of the [[blues scale]] to [[Musical mode|modal scales]] and partly from the characteristics of the guitar and the use of parallel major chords on the [[pentatonic minor scale]]. With [[barre chord]]s on guitar, the same chord shape can be moved up and down the neck without changing the fingering. This phenomenon is also linked to the rise in use of [[power chords]] in various sub-genres of [[rock music]].

==See also==
* [[Chromatic mediant]]
* [[Diatonic function]]
* [[Ear training]]
* [[List of chord progressions]]
* [[List of songs containing the 50s progression]]
* [[List of songs containing the I–V–vi–IV progression]]
* [[Montgomery-Ward bridge]]
* [[Passamezzo moderno]]
* [[Passing chord]]
* [[Root progression]]s
* [[Sequence (music)]]
* [[Twelve-bar blues]]
* [[Traditional sub-Saharan African harmony]]

==References==
{{reflist}}

==Further reading==
* Lloyd, Peter (2014). ''The Secret Life of Chords: A guide to chord progressions and composition''. Australian eBook Publisher. {{ISBN|9781925029765}}.
* Middleton, Richard (1990/2002). "Studying Popular Music". Philadelphia: Open University Press. {{ISBN|0-335-15275-9}}.
* Nettles, Barrie & Graf, Richard (1997). ''The Chord Scale Theory and Jazz Harmony''. Advance Music, {{ISBN|3-89221-056-X}}.
* R., Ken (2012). ''DOG EAR Tritone Substitution for Jazz Guitar'', Amazon Digital Services, Inc., ASIN: B008FRWNIW

{{Chord progressions}}
{{harmony}}

{{DEFAULTSORT:Chord Progression}}
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