Editing Chord progression (section)

===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]]".