Backdoor progression
Injazzandjazz harmony,thechord progressionfrom iv7to♭VII7to I (the tonic or "home" chord) has been nicknamed thebackdoor progression[1][2]or thebackdoor ii-V,as described by jazz theorist and authorJerry Coker.This name derives from an assumption that the normal progression to thetonic,theii-V-I turnaround(ii-V7to I, see alsoauthentic cadence) is, by inference, the "front door", a metaphor suggesting that this is the main route to the tonic.
The♭VII7chord, apivot chordborrowedfrom theparallel minorof the current tonic major key, is adominant seventh.Therefore, it can resolve to I; it is commonly preceded by IV going to iv, then♭VII7,then I. In C major the dominant would be G7:(the notes GBDF), sharing twocommon toneswith B♭7:(the notes B♭DFA♭). The notes A♭and F serve as upperleading-tonesback to G and E (when the chord moves to the tonic, C major), respectively, rather than B♮and F serving as the lower and upper leading-tones to C and E in a conventional G7-C major (V7-I) cadence.
Abackdoor IV-Vis also possible, moving from♭VIM7to♭VII7to I. This is also commonly known as "Mario Cadence".[3]
Alternative usage
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The term "Backdoor" has been used by author Shelton Berg to refer to another entirely unrelated progression. The unexpectedmodulationcreated through thesubstitutionof the highly similar Imaj9for iii7(in C: CEGBD and EGBD) at the end of the iiø7-V7turnaround to a tonicizediii(iiø7/iii=♯ivø7,V7/iii=VII7,iii), arrives at 'home' (the temporary tonic of iii) through unexpected means, the 'back door' instead of the 'front door'(iii7,the individual notes EGBD, being entirely contained within Imaj9,the individual notes of the C major chord, CEGBD, and theseventhof the dominant seventh chord still resolving downward).[4]The resolution of a dominant seventh chord up a step (in this case a half-step, also called a semitone) is called adeceptive cadence.
See also
[edit]References
[edit]- ^Coker, Jerry (1997).Elements of the Jazz Language for the Developing Improvisor,p.82.ISBN1-57623-875-X."Back Door Progression As A Substitute For V7[:] The I chord, in a given progression, is often preceded by IV-7 to♭VII7,instead of the usual V7 chord.".
- ^Juusela, Kari (2015).The Berklee Contemporary Dictionary of Music,unpaginated. Hal Leonard.ISBN9781495028540."back-door cadence: A IVmi7♭VII7 I harmonic cadence. "
- ^Lavengood, Megan (July 1, 2021)."Open Music Theory: Modal Schemas"– via viva.pressbooks.pub.
{{cite journal}}:Cite journal requires|journal=(help) - ^Berg, Shelton (2005).Essentials Of Jazz Theory,p.105. Alfred Music.ISBN0-7390-3089-2.