Editing Chord progression (section)

==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]].