Tritone substitution--please explain!

[HumanFuseBen]

I've heard the term tritone substitution about a zillion times and have never had someone explain it well or show me some examples. could someone do just that, please? explain what it is, then give me a few chord progressions that utilize it, maybe something in the key of C.

 

Thanks a bunch!

[Jed]

 

I've heard the term tritone substitution about a zillion times and have never had someone explain it well or show me some examples. could someone do just that, please? explain what it is, then give me a few chord progressions that utilize it, maybe something in the key of C.

 

 

It's actually pretty easy. Take the key of C major. The V7 chord is a G7, spelled G B D F. The interval from B to F is a tritone, equal to 3 whole-steps, also known as a diminished 5th. As it turns out these two notes of the tritone (the maj 3rd and minor 7th of the G7 chord (think tension)) strongly push the ear towards the C major chord (think release).

 

But what happens if we turn things upside down? The inversion of a diminished 5th is an augmented 4th (also a tritone). In our case the inversion would be the notes F and B. Note that B is enharmonic (same pitch different name) to a Cb. So let's use the Cb rather than the B to see what kind of chord we get.

 

So we have the notes F and Cb as they function in the progression pushing us towards the C major sound. As it turns out, a Db7, spelled Db F Ab Cb, uses the same notes that were so powerful in the G7 (G B D F). So what would happen if instead of playing the G7 we substituted a Db7? Again this chord still pushes us towards the C major. A Db7 is called the sub-V7 of G7, aka the tritone substitution.

 

To find a tritone sub for any dominant chord, just build a dominant chord on the b5 (or the #4) of the original dominant chord. Not too hard to understand I hope.

 

V7 > subV7

 

C7 > F#7 = Gb7

F7 > B7 = Cb7

Bb7 > E7 = Fb7

Eb7 > A7 = Bbb7

Ab7 > D7 = Ebb7

Db7 = G7 > Abb7

F#7 > B#7 = C7

B7 > E#7 = F7

E7 > A#7 = Bb7

A7 > D#7 = Eb7

D7 > G#7 = Ab7

G7 > C#7 = Db7

 

 

cheers,

[Cloud_9]

Jed is spot on.

 

Flat five substitution is a great musical tool to use in your compositions, I use it frequently.

 

Some further study......

 

http://guitar.ricmedia.com/Music-Theory/Flat-five-substitution/

http://www.torvund.net/guitar/index.php?page=bl_flatfive_01

 

Peace:thu:

[3shiftgtr]

 

To find a tritone sub for any dominant chord, just build a dominant chord on the b5 of #4 of the original chord. Not too hard to understand I hope. cheers,

 

 

As usual Jed da man. But a typo clarification maybe? Doncha mean "...just build a dominant chord on the b5 (or #4) of the of the original chord"?? Cuz if the chord is G7, and you build a dominant chord on the b5 of #4 of the original chord, you are building a dominant chord on the same dominant chord. The b5 of the # 4 of G is G. The #4 of G is Db and the b5 of Db is G.

 

So simply put, on a V7 chord, you can build another dominant chord a tritone away from the V7, for all the reasons Jed so eloquently (as usual) said.

[3shiftgtr]

Here's a cool standardized example:

 

Let's say our standard progression goes Dm7, G7, Cmaj7 which is a iim7, V7, I in Cmaj.

 

Instead of going to the G7, do a 7 chord on the tritone of G7, which would be Db7. The tritone sub of G7 is Db7, so the progression now goes:

 

Dm7, Db7, Cmaj7 Boom! Now you can wear the beret with pride.....

 

A cool 'extended' twist/trick that sounds cool that works in the same context:

 

Same iim7, V7, I in C. Except you changed the G7 to G13. Since they're both dominant, it's o.k., as long as it doesn't hurt the melody. This works on guitar alot. Progression is now Dm7, G13, Cmaj7.

 

So how do you b5 sub for a V13??

 

Well, as explained earlier, the b5 sub of G7 is Db7. But what about the 13? Well, the 13nth of G is an E note, and if you add it to the Db7 chord it becomes a Db7#9! The Hendrix "Purple Haze" chord! So you've got:

 

Dm7, Db7#9, Cmaj7

 

And even if the V is just a 7 and not a 13, it still works (almost) all the time on guitar.

 

And now you don't HAVE to wear the beret....

 

Btw, I left a lot of theory detail explanation out of the "trick", just to help keep ya movin'....

[HumanFuseBen]

huh, very cool! so anytime i am going to the V7 chord, i can just play another 7 chord a flat 5th up... swift. i'm going to give that a try! thanks a ton!

[Jed]

 

. . But a typo clarification maybe? Doncha mean "...just build a dominant chord on the b5 (or #4) of the of the original chord"?? Cuz if the chord is G7, and you build a dominant chord on the b5 of #4 of the original chord, you are building a dominant chord on the same dominant chord. The b5 of the # 4 of G is G. The #4 of G is Db and the b5 of Db is G. So simply put, on a V7 chord, you can build another dominant chord a tritone away from the V7, for all the reasons Jed so eloquently (as usual) said.

 

 

Yes, exactly. I should have said "...just build a dominant chord on the b5 (or #4) of the original chord". Thanks for the correction. I had a nagging suspicion that I had a typo in there but I could not find it. I'll edit the original post a bit later.

 

cheers,

[Jed]

 

huh, very cool! so anytime i am going to the V7 chord, i can just play another 7 chord a flat 5th up... swift. i'm going to give that a try! thanks a ton!

 

 

Another way to think is that the subV7 approaches it's target from a half-step above. So for the progression - Dmin7 G7 Cmaj7 - using the subV7 for the G7 yields - Dmin7 Db7 Cmaj7 - note the descending chromatic line. (from previous example)

 

So we can also say (about subV7's) that the subV7 for any target comes from a half-step above the target. (rather than thinking from the b5 of the V7 chord)

 

think - Target = Cmaj7, subV7 = Db7 - play Db7 > Cmaj7

think - Target = Fmaj7, subV7 = Gb7 - play Gb7 > Fmaj7

Target = Bbmaj7, subV7 = Cb7 aka B7

Target = Ebmaj7, subV7 = Fb7 aka E7

etc

 

So if we take this new twist and project in onto the concept of extended secondary dominant runs (G7 > C7 > F7 > Bb7 > Eb7, etc)

 

. . . we can get an extended run of subV7 resolutions: G7 > Gb7 (or F#7) > F7 > Fb7 (or E7) > Eb7 > D7, etc

 

cheers,

[meganutt7]

Another thing that is often done with tritone subs is extending them "backwards", meaning, taking the ii chord that would have preceded the tritone sub of the V chord.

 

Meaning, if your progression is:

 

Dm7 /G7 /Cmaj7

 

you can play the regular tritone sub:

 

Dm7 /Db7 /Cmaj7

 

or with the "ii":

 

Dm7 /Abm7 Db7 /Cmaj7

 

Or even further (to include the Dm7)

 

Abm7 /Db7 /Cmaj7

 

Of course, this also means you can freely apply the MELODIC counterparts of this concept wether the accompanist is playing the substitutions or not...

 

Meaning, if the implied prgression is Dm7-Db7-Cmaj7

 

you can play: D Dorian, then Db Altered or Db Lydian b7 or Db Phrygian Dominant or Db symmetrical diminished (half whole), or Db whole tone, etc. etc., then to C major or C Lydian.

 

Interesting no?? I think so...

[lollygag]

If you take a 7th chord, like G7 (g,b,d,f) it shares almost all its notes with the dominant 7b5 chord a tritone away (in this case, C#, F, g, b).

[bebeskid87]

if you are on keys on thing i like to do with tri-tones is play them over a major Chord like if your playing a Ab instead of playing Ab in the bass you can play a E-Bb in left hand but make sure to play in 2nd inversion so that the C is at the top of the chord so E-Bb in bass hand Eb-Ab-C in right hand

[VagueSubscription]

Just go up a augmented 4th from the 5th note of the scale, that is the root note for the dom7.

 

In other words, let's say you have an ii V7 chord progression,  Am7 - D7. Instead of D7, you'd substitute a G#7 for the D7. G# being an augmented 4th above D.

So let's say you're vampin' away on this Am7 -D7 progression, when you want to end the song. Try Am7 G#7 GMaj7 (5th fret, 4th fret, 3d fret). You'll hear how nicely that progression "walks", to the ending.