9/13/05

Special Function Dominant Chords

Special function dominants are dominant seventh chords that do not resolve down a fifth or down a half step. These dominants have reasonably strong resolutions to tonic Imaj7 chords and can be used by the improviser or arranger as substitutes for V7 chords. Though these special function dominant chords do not have as strong resolutions as V7s or subV7s, they are strong enough to be used as subs for these chords. SFD chords can be used to create a more desired bass line or to harmonize hard to voice melody notes. They can also be used by the improviser to create interesting reharmonized lines over existing chord changes. One thing to keep in mind when you are creating reharmonized lines or chord changes is that you may always precede these SFDs with their related ii-7s.

Here are the Special Function Dominants:

  • I7 this is used in blues progressions as a tonic dominant. It also sometimes resolves to the Imaj7 tonic.
  • II7 this chord is closely related to the bVI7 and the #IV-7b5 (they all share the same tritones). It is normally analyzed as V7/V (secondary dominant function), except when it resolves directly to I when it acts as a SFD.
  • IV7~ used in blues progressions, resolves to a I7. IV7 is diatonic to melodic minor, and has a subdominant function in that context.

Blues context: /C7 /F7 /C7 F7 /C7
Minor context: /C-6 G7(b13)/ C-6 F7/ C-6 /

  • bVI7 ~ usually analyzed as a sub V7/V. When resolved directly to I it creates a special function cadence. This chord is derived from the chromatic harmony of the 19th century. This chord is closely related to the IV- chord, although it is not diatonic to the minor key. This chord is said to have an altered subdominant minor function.
  • VII7 ~this is usually analyzed as a V7/III, except when it resolves directly to I. Since VII7 is not associated with any particular area within the key, its function is simply cadential.
  • bVII7 ~this chord is derived from natural minor and has a subdominant minor function. This is an example of modal interchange. The IV-7 is often used with the bVII7 in a subdominant minor pattern like so: /C- /F-7 Bb7/C- //

How do we apply this knowledge?
As improvisers, we need to be able to create valid and functional chord progressions on the fly. Special function dominants can help us do this.

  • We can add SFDs after V7s, before resolving to I:
/D-7 G7/Ab7 Cmaj7/
This creates a delayed resolution, which is always interesting.
  • We can use them at the very end of a tune for a candenza, right before the last chord of the tune.
  • We can add the SFD's related ii-7 and substitute or add to an existing ii-7/V7/I:

/D-7 / G7 /Cmaj7 / (original)
/F-7 /Bb7 /Cmaj7 / (substitute)
/D-7 G7/F-7 Bb7/Cmaj7 /

  • We can also use them as passing chords to break up a bland Imaj7 section in a tune:

/G7 / Cmaj7 /Cmaj7 / Cmaj6 / (original)
/G7 / Cmaj7 Ab7 /Cmaj7 D7 /Cmaj6 / (with SFDs)
/G7 /Cmaj7 Eb-7 Ab7/Cmaj7 A-7 D7 /Cmaj6 / (with added related ii-7s)

The best way to get used to the sound of the SFD chords is to sit down at a piano or with a guitar and play through all of them. Try playing them one at a time and resolving to Imaj7 after each one.

For example:
Cmaj7 /C7 /Cmaj7 /D7 /Cmaj7 /F7 /C7 /Ab7 /Cmaj7 /Bb7 /Cmaj7 /B7 /Cmaj7 //

4 comments:

Dan said...

Actually, the VII7 does function as a V7/iii when it resolves to one, insofar as iii is an upper structure of IMaj7, and therefore can be a functional substitute for it.

This is related to one of the ways I think of the diminished substitution axis (4 tonic system):

D-7 G7 - Basic Diatonic
F-7 Bb7 - Minor Subdominant/Backdoor Progression
Ab-7 Db7 - Tritone Substitution of Diatonic
B-7 E7 - Relative Minor

So, a Bm7(b5) to E7(b9) can resolve to C, because A-7 is C6. So if the line resolves to A-7, it can be used wholesale over D-7 G7 C6. So if E7 resolving to Amin works over C, B7 resolving to Emin works for a similar reason. It would be interesting to see if somebody figured a way to use the B-7 E7 as a tritone substitution of F-7 Bb7 in a C major context. I like trying all the different ways of trying to fit the #5/b6 into a diatonic context.

Dan

David Valdez said...

This 4 tonic system of substitution is covered in my earlier post called 'Slonimsky's Symmetrical Scales-Diminished, Wholetone'. Good point about the V7/iii being both a SFD and a secondary dominant. Thanks, Dan

Hucbald said...

Excellent post. I love things that get me thinking "outside the box" that traditional theory sometimes puts me in. It's been so many years since I was at Berklee that I'd forgotten about SFD's. The ||F- Bb7|C (triad)|| is particularly compelling with traditional voice leading. And, it just so happens, I have a guitar sonata that will fit nicely into. ;^) Cheers David.

Viqi French said...

my... all very deep and academic. good to see talent in the jazz mart. i don't know a dominant from a vomitted, so keep doing what you're doing!