Editing Twelve-bar blues (section)

==Variations==
=== Shuffle blues ===
In the original form, the dominant chord continued through the tenth bar; later on, the V–IV–I–I "shuffle blues" pattern became standard in the third set of four bars:{{sfn|Gerow|Tanner|1984|p=37|ps=: cited in Baker 2004: "This alteration [V–IV–I rather than V–V–I] is now considered standard."}}
:{|class="wikitable" style="text-align:center; width:130px;"
|width=25%|I
|width=25%|I
|width=25%|I
|width=25%|I
|-
|width=25%|IV
|width=25%|IV
|width=25%|I
|width=25%|I
|-
|width=25%|V
|width=25%|'''IV'''
|width=25%|I
|width=25%|I
|-
|}

{{Listen|filename=Twelve_bar_boogie-woogie_blues_in_C.mid|title=Twelve bar boogie-woogie blues in C|plain=yes|style=margin-left:1em}}

=== Quick to four ===

{{anchor|quick-change}}

The common quick-change, quick to four, or quick four variation uses the subdominant or IV chord in the second bar.{{sfn|McCumber|2006|p=25}}
:{|class="wikitable" style="text-align:center; width:130px;"
|width=25%|I
|width=25%|'''IV'''
|width=25%|I
|width=25%|I
|-
|width=25%|IV
|width=25%|IV
|width=25%|I
|width=25%|I
|-
|width=25%|V
|width=25%|IV
|width=25%|I
|width=25%|I
|-
|}

=== Seventh chords ===
Seventh chords are a type of chord that includes the 7th scale degree (that is, the 7th note of the scale). There are different types of 7th chords such as major 7ths, dominant 7ths, minor 7ths, half diminished 7ths, and fully diminished 7ths.<ref>{{cite journal|url=https://milnepublishing.geneseo.edu/fundamentals-function-form/chapter/18-seventh-chords/|last=Mount|first=Andre|title=Seventh Chords|website=Milnepublishingonline|access-date=November 29, 2021}}</ref> These chords are similar with slight changes, but are all centered around the same key center. Dominant 7th chords are generally used throughout a blues progression. The addition of dominant 7th chords as well as the inclusion of other types of 7th chords (i.e. minor and diminished 7ths) are often used just before a change, and more changes can be added. A more complicated example might look like this, where "7" indicates a seventh chord:

:{|class="wikitable" style="text-align:center; width:130px;"
|width=25%|I
|width=25%|IV
|width=25%|I
|width=25%|I<sup>7</sup>
|-
|width=25%|IV
|width=25%|IV<sup>7</sup>
|width=25%|I
|width=25%|I<sup>7</sup>
|-
|width=25%|V
|width=25%|IV
|width=25%|I
|width=25%|V<sup>7</sup>
|-
|}

=== Bebop blues ===
This progression is similar to [[Charlie Parker]]'s "[[Now's the Time (composition)|Now's the Time]]", "[[Billie's Bounce]]", [[Sonny Rollins]]'s "[[Tenor Madness]]", and many other [[Bebop|bop]] tunes.{{sfn|Spitzer|2001|p=62}} Peter Spitzer describes it as "a bop [[Solo (music)|soloist's]] cliche to [[arpeggio|arpeggiate]] this chord [A<sup>7{{music|b}}9</sup> ([[secondary dominant|V/ii]] = VI<sup>7{{music|b}}9</sup>)] from the [[third (chord)|3]] up to the {{music|b}}[[ninth|9]]."{{sfn|Spitzer|2001|p=62}}
:{|class="wikitable" style="text-align:center; width:250px;"
|width=25%|I<sup>7</sup>
|width=25%|IV<sup>7</sup>
|width=25%|I<sup>7</sup>
|width=25%|V<sup>7</sup> I<sup>7</sup>
|-
|width=25%|IV<sup>7</sup>
|width=25%|{{music|#}}IV{{music|dim}}<sup>7</sup>
|width=25%|I<sup>7</sup> 
|width=25%|V/ii<sup>{{music|b}}9</sup>
|-
|width=25%|ii<sup>7</sup>
|width=25%|V<sup>7</sup>
|width=25%|I<sup>7</sup> V/ii<sup>{{music|b}}9</sup>
|width=25%|ii<sup>7</sup> V<sup>7</sup>
|-
|}
{{Listen|filename=Bebop_blues_progression.mid|title=Bebop blues progression|plain=yes|style=margin-left:1em}}

=== Minor blues ===
There are also minor twelve-bar blues, such as [[John Coltrane]]'s "[[Equinox (standard)|Equinox]]" and "[[Mr. P.C.]]".{{sfn|Spitzer|2001|p=63}} The chord on the fifth [[degree (music)|scale degree]] may be major (V<sup>7</sup>) or minor (v<sup>7</sup>).{{sfn|Spitzer|2001|p=63}} Major and minor can also be mixed together, a signature characteristic of the music of [[Charles Brown (musician)|Charles Brown]].{{sfn|di Perna|1991|pp=180, 80|ps=: "Brown alternates between an Fmin7 and a B7. Minor to major, just like the man says."}}
:{|class="wikitable" style="text-align:center; width:180px;"
|width=25%|i<sup>7</sup>
|width=25%|i<sup>7</sup>
|width=25%|i<sup>7</sup>
|width=25%|i<sup>7</sup>
|-
|width=25%|iv<sup>7</sup>
|width=25%|iv<sup>7</sup>
|width=25%|i<sup>7</sup> 
|width=25%|i<sup>7</sup>
|-
|width=25%|{{music|b}}VI<sup>7</sup>
|width=25%|V<sup>7</sup>
|width=25%|i<sup>7</sup>
|width=25%|i<sup>7</sup>
|-
|}
{{Listen|filename=Minor_blues_progression.mid|title=Minor blues progression|plain=yes|style=margin-left:1em}}

===Other variations===
"[[W. C. Handy]] codified this blues form to help musicians communicate chord changes."{{sfn|Jackson|2002|p=18}} Many variations are possible. The length of sections may be varied to create [[eight-bar blues]] or [[sixteen-bar blues]].

[[Image:Standard 12-bar blues progression variations.png|center|Standard twelve-bar blues progressions variations, in key of C.{{sfn|Benward|Saker|2003|p=}} {{audio|Standard 12-bar blues progression variations A.mid|Play A}}, B, {{audio|Standard 12-bar blues progression variations C.mid|C}}, {{audio|Standard 12-bar blues progression variations D.mid|D}}, and {{audio|Standard 12-bar blues progression variations E.mid|E}} as boogie woogie basslines.|alt=|frame]]