Tritone Substitution Question

[recneps15]

In the "Chromatics" lesson, they use tritone substitution in the ii-V-I progression in the examples. I understand how in example 3 (using the tritone lesson), the G7 can be substituted by the Db7, and that creates a chromatic line from D to C.

I don't understand how tritone substitution is used to substitute Dm7 by Ab7. The b3 and b7 from Dm7 are not a tritone. When I make the C the b3, and the F the b7, the root and 5th end up being different depending on whether I start from the C or the F.

I read about "imperfect/general" tritone substitution, where the root of the substitution is a tritone of the original chord's root. I think that's what this is because Ab is 6 half steps above D. If this is the case, why does the chord change from a Minor 7th to a Dominant 7th?

[mr. beaumont]

it's treating the "D" chord as if it were a secondary dominant--ie, D7, G7, Cmaj in the key of C. D is the "V" of "V", so Ab7 is the tritone sub based on that--the chromatic movement in the bass is the most desirable thing there.

It's a little bit more of a "delicate" sub, IMHO--the kind you might want to let folks know about ahead of time if you're going to do.

[Tom Karol]

Here's another aspect to the ii-V-I thing (in C):
If you use the sub-V (Db7) instead of the V7 (G7), you can also (sometimes) precede it by its related ii (Abm7) instead of the ii (Dm7).
Wes used to do this.
As Mr. B. aptly said, it's really all about root motion.
Hope that doesn't just add to the confusion!

[Reg]

Also in jazz harmony, modal interchange is one of the main sources of re-harmonization. A re-harmonization is different than chord substitution. Usually... Chord sub. has same function and is built from same collection of notes. The re-harm. may or may not have same function or same collection of notes. In the example the replacement of G7 by Db7 is a re-harm. by means of tri-tone substitution, same dominant function, different collection of notes, (there are other methods of analysis of Db7). The original D-7 could by means of modal interchange be re-harm. to D7 and them tri-tone substitution to become Ab7. All this would usually be if melody permits. In traditional theory... secondary dominants or use of chord sequences are methodologies of re-harmonization, which the Ab7 could be explained... in jazz, modal interchange is much more common and your example is very common...Best Reg

[lkmuller]

Originally Posted by Tom Karol

Here's another aspect to the ii-V-I thing (in C):
If you use the sub-V (Db7) instead of the V7 (G7), you can also (sometimes) precede it by its related ii (Abm7) instead of the ii (Dm7).
Wes used to do this.
As Mr. B. aptly said, it's really all about root motion.
Hope that doesn't just add to the confusion!

Martino does this in his "All Blues" from hi Live At Yoshi's CD. Eb dorian to Ab jazz monor to take him to the IV, C7.

[billkath]

Looks more like a passing chord to me. But..as Manuel would say...I know na-thing!

[Reg]

Hey Aleikhbaba... The tri-tone sub is just that... Eb7 is a tri-tone sub for A7.
What actually happens is the 3rd and 7th of A7, (C# and G) is inverted, or spelled, G and Db(C#), and chord becomes Eb7. Which is the SubV of D7. So in principle, any chord can be preceded by it's SubV, which is a Tri-tone sub for the V chord of actual target chord, in your example, D7. In jazz, any V7 chord can be preceded by it's II- chord. In your example the Eb7 could be preceded by Bb-, the D7 could also have A- before. The II- V7 is regarded as a single unit, but you have the freedom to play around with chords depending on context. The next step is to use the same concept, but use only the root motion and change the chord by means of modal interchange... In theory you can take a sub-V, or it's related II-, in your example the Eb7 chord and through Modal interchange, change Eb7 to a Eb-7, their are methodologies or Jazz rules when using MI, but that's another subject. So it's not simply root motion. But root motion is a simple system of recognizing end result... and easy, but many flaws.
Some more notes on Dominant chords...
A dominant chord resolving to I has Dominant cadence
A dominant chord resolving to chord other than I, has Dominant resolution
Secondary Dominants resolve to Diatonic chords other than I
Extended Dominants resolve to to secondary Dom. or another extended Dom. or related II-
Best Reg

[Claudi]

Originally Posted by Reg

Extended Dominants resolve to to secondary Dom. or another extended Dom. or related II-
Best Reg

What are Extended Dominants? It's the first time I hear/read about that.
And are there any other dominants besides simple dominants, secondary and extended?

[jazzuki]

The bass line steers the progression-usually in cycle of 4ths

[docbop]

Originally Posted by Claudi

What are Extended Dominants? It's the first time I hear/read about that.
And are there any other dominants besides simple dominants, secondary and extended?

From Wikipedia

An extended dominant is a non-diatonic dominant 7th chord that resolves downwards to another dominant chord. A series of extended dominant chords continues to resolve downwards by perfect 5ths until they reach the tonic chord.

Typically used in jazz, extended dominants have been used in other contexts as well.

[Reg]

In jazz... extended Dominants can resolve downward or upwards, to another Dominant chord or a Dominant chords related II-. If you resolve downward, interval would be P5th, if upward, the interval would be P4th. In jazz... extended Dom. are not required to reach the tonic chord.
B7, E7......., A7, D7......, G7. series of extended Dominants
B7, B-7 E7, A7, A-7 D7, G7. ext. Doms. with related II-
B7, E-7......, A7, D-7....., G7. ext. doms. with II- , can still be heard as ext. Dom.
Depending on context... analysis can always change. The resolution of tri-tones in ext. Doms. can be actual or implied. With use of modal interchange can become very deceptive....Reg

[Claudi]

Originally Posted by docbop

From Wikipedia

An extended dominant is a non-diatonic dominant 7th chord that resolves downwards to another dominant chord. A series of extended dominant chords continues to resolve downwards by perfect 5ths until they reach the tonic chord.

...but a dominant is a dominant, be that in the diatonic scale or in the harmonic minor, in the harmonic major and in the melodic minor (unless the altered dominant).

Originally Posted by docbop

Typically used in jazz, extended dominants have been used in other contexts as well.

Which other contexts? Think that I didn't know anything about it until now. I'll have a look at the wiki but I'm looking forward your answers, ok? Thanks for your answers.

[Claudi]

Originally Posted by Reg

In jazz... extended Dominants can resolve downward or upwards, to another Dominant chord or a Dominant chords related II-. If you resolve downward, interval would be P5th, if upward, the interval would be P4th. In jazz... extended Dom. are not required to reach the tonic chord.
B7, E7......., A7, D7......, G7. series of extended Dominants
B7, B-7 E7, A7, A-7 D7, G7. ext. Doms. with related II-
B7, E-7......, A7, D-7....., G7. ext. doms. with II- , can still be heard as ext. Dom.
Depending on context... analysis can always change. The resolution of tri-tones in ext. Doms. can be actual or implied. With use of modal interchange can become very deceptive....Reg

When you guys say to resolve downwards you mean descending and resolving upwards you mean ascending, right?
Hey, reg. I agree with your last sentence. When I try to play chords modally it seems that I play whatever. Sounds jazzy but as if I were playing chords randomly, no rule in there.

[Reg]

Please make a copy of this for reference, thanks

1) a dominant chord resolving, (going to) I chord has Dominant cadence.
ex. key of C;......... G7 going to Cmaj, V7 Imaj
2) a dominant chord resolving to other chord than I, has Dominant resolution.
ex. key of C;..... dom7th chord going to any chord, besides C.
3) Secondary dominants resolve to Diatonic chords other than I.
ex. key of C; a dom7th chord going to any diatonic chord,(D-7,E-7,Fmaj7, G7,A-7,B-7b5, chords built on scale degrees from key of Cmaj.) OTHER THAN Cmaj. Cmaj. being the I chord.
4 Extended Dominants resolve to...A)secondary Doms. B) another extended dom. C) the related II- of another extended or sec. Dom.
A7, D7, G7, Cmaj7....... A7 is ext. dom., D7 is sec. dom., (V7/V7), G7 is V7 of Cmaj7, (Imaj7)

B7, E7......., A7, D7......, G7. series of extended Dominants... No I chord
B7, B-7 E7, A7, A-7 D7, G7. ext. Doms. with related II-..........no I chord
B7, E-7......, A7, D-7....., G7. ext. doms. with II-......................no I chord
This is typical use in Jazz.

Hey Claudi...
When we use ascending and descending, were making reference to root motion. The resolution really means some type of resolution of intervals in chords, but we use the term loosely and many time are simply referring to chord going to another chord .
Modal interchange is a methodology used for chord substitution.
Playing chords modally would be using chords with modal concepts, each mode has different characteristic notes and interval resolutions, different than, say like playing in Cmaj, which uses tri-tone as part of characteristic Dominant resolution. Best Reg

[Claudi]

Thank you, reg.
Your points on extended dominants are the ones I didn't know since you already posted the other ones.
Y'know, it seems that when I think I know what's going on something new appears, like these extended dominants. I wonder what will be the next new thing that will appear.

[docbop]

The term extended dominants is new to me, but seeing the description its just a way of saying your proceeding a chord with its own V. Basically you can precede any chord by a dominant a 5th up. So lets say you have a II chord in C major Dmi7 you could put "its V" an A7 before it. Reg's post has all the proper names for this, I'm just trying show simply what it is. It works because it has the V->I root movement/sound, it's resolving. Where I come from we would say its a "functioning" dominant, its acting like a V because it moving down a 5th. This is what the Circle of Fifths is all about. I've seen it noted as V of II and other similar notation.

You can put more than one dominant before a chord we called that "back cycling". that would something like B7->E7->A7->D-7. All dominants a fifth apart so they each have that V->I sound.

Bottom line its all about root movement.

[Reg]

Bottom line its all about root movement.[/quote]

It can be.... Different types of Dom. chords have different collections of notes, which are related to context and the resolutions of inner voices, and they fall into different groups....But who cares... Most don't hear the difference anyway. When I play... I play what the group plays... Different groups play differently... Reg