Tritone Subs: when and how?

[PSA]

This was mentioned recently in a thread inquiring about tritones. I've been getting into jazz for a year or so now, but I still to this day do not understand tritone subs. first of all, what are they? I kinda know, but rehash would be good. But here's my big problem: when do you use them? I mean, you certainly don't just through them in at random, do you? what function do they serve?

 

thanks

 

Ellen

[Terje]

OK, tritone subs... it's not so mystical as some want it to sound, it's about getting a different, and often chromatic, bassline. The idea is that in a dominant chord (let's say G7) the tritone relation between the 3rd and the b7th of the chord (B and F) is what really gives the chord it's quality of being a dominant chord. This is because both these notes, B and F, lead to the root and the 3rd of the tonic chord (C in this case, the notes being C and E).

 

Now, to these two notes in the dominant chord you can basically add anything and it'll still work. Now the "magic" is that a tritone away from G7 there is another dominant chord, C#7, that shares the same tritone (B and F), just that their relationship to the root of the new chord is inverted.

 

So you can play C#7 instead of G7 and in many cases it'll sound fresh and good. Let's just look at a few examples in a regular jazzy 12-bar blues though, cause then you can see what's happening (and hear it too if you play the progression). First the normal one:

|C7|F7|C7|Gm7 C7|F7|F7|C7|A7|Dm7|G7|C7|Dm7 G7|

 

Now let's just makes a two simple tritone subs, that really show what it's all about:

|C7|B7|C7|Gm7 C7|F7|F7|C7|A7|Dm7|C#7|C7|Dm7 G7|

 

What these two simple subs give you is a chromatic bass line. But since the new chord has the same tritone as the original one it'll sound, and especially function, very much in the same way as the original chord.

 

Now here's another cool thing. You don't have to tell the band this. You can do these changes on top of the original harmony. It'll sound altered, but once you get the hang of it you'll think it sounds cool.

 

So, over the G7 chord, for instance, you can play the notes from the C# mixolydian scale. There are lots of other ways of getting this altered sound, and this is perhaps not the easiest one, but let's leave it at that for now. You get the idea I think.

[WattsUrizen]

Good answer Terje.

 

I think it's also worth noting the influence of melodic and contrapuntal factors in tritone substitutions.

 

If you make a tritone substitution on the dominant chord, then the new chord will be one semitone higher than the tonic. This is really a very nice situation which highlights the power of tritone substitutions.

 

By making the substitution we introduce a foreign sound, and thus the tension is increased quite noticeably. However, since the resolution to the tonic is a descending minor second, we have a very smooth voice leading, and so the tension is released.

 

Obviously in this context, the tritone substitution is most effective in highlighting the dominant to tonic movement, since in between these two chords, we introduce a foreign chord which increases tension even further, thus making the tonic a very strong point of stability.

 

Also, since the tritone substitution is one semitone above the tonic, we can also voice it as a Neopolitan Sixth, with an added flat fifth, and this can lead into all manner of crazy stuff.

 

The point being that while jazz players are mostly concerned with the harmonic properties of the tritone substitution, many of its most fascinating applications arise from melodic and contrapuntal factors.

[Terje]

 

Originally posted by Anomandaris Good answer Terje. I think it's also worth noting the influence of melodic and contrapuntal factors in tritone substitutions. If you make a tritone substitution on the dominant chord, then the new chord will be one semitone higher than the tonic. This is really a very nice situation which highlights the power of tritone substitutions.

 

 

It's when I realized this that I understood the value of tritone subs. And I first understood that when I did these two subs in a 12-bar blues.

[thamiam]

I see I'm not needed here...

[PSA]

okay, so you can use the tritone sub for any dominant chord, not just the V of the key your in? man, my theory is terrible. how do you guys get all this stuff in your head? Is there a magic book or something? And you can actually think this stuff up as you're playing? how long and what did it take to be able to do that?

 

Also, what on earth is a Neopolitan 6th? I only partially follow all this talk, it's not at all concrete in my mind. I guess I'll just have to play around with it...

 

thanks for the replies - I'm sure they're very good, I just have to take a nap and read them a few more times.

[Macblah-1]

A Neopolitan 6th is the first inversion of a major chord built on the b2nd of the tonic. So in the key of C major the notes for a N6 would be F G# C#. What has this to do with tritone subs?? The tritone sub chord for a G7 (V7 in c major) would be C#7, which has the notes C# F G# B. So now you see that the C#7 has all the notes of the N6, and a B (b5 of the N6, remember, F is considered as the root of the N6 chord).

[WattsUrizen]

Originally posted by thamiam I see I'm not needed here...

 

Please, post. I'd be interested to hear your views on this, and some of your ideas on their applications.

[WattsUrizen]

 

Originally posted by PSA okay, so you can use the tritone sub for any dominant chord, not just the V of the key your in?

 

 

You can do whatever you want. But tritone subs are most effective in a dominant situation. Whether this is a secondary dominant, or the 'true' dominant, doesn't matter.

[thamiam]

Originally posted by Anomandaris Please, post. I'd be interested to hear your views on this, and some of your ideas on their applications.

 

As far as tritone substitutions go, my views are right in line with Terje's first response.

 

The only thing is that in a band situation, if you consistently use tritone substitutions the band might get a little pissed at you. Mixing up tritone subs and 'standard' ii-V-I's is usually preferred.

 

Here is a fantastic page about substitutions, turnarounds and other frequent progression devices.

 

http://cc2.hku.nl/wim/reservoir/ict-b/analyse/hearin.html

[WattsUrizen]

Originally posted by thamiam As far as tritone substitutions go, my views are right in line with Terje's first response. The only thing is that in a band situation, if you consistently use tritone substitutions the band might get a little pissed at you. Mixing up tritone subs and 'standard' ii-V-I's is usually preferred. Here is a fantastic page about substitutions, turnarounds and other frequent progression devices. http://cc2.hku.nl/wim/reservoir/ict-b/analyse/hearin.html

 

I get worried when those sorts of pages talk about chord progressions going through a series of modulations. Modulation doesn't work like that. Chromaticism in passing chords is not modulation.

 

But anyway, that's only what I looked at in the tritone subs sections. I'll have to read through that thoroughly. My jazz theory is really bad. Thanks for that.