Answer to Question on Tritones

Question from Michael Bell:


Thanks for the site it's proving to be very helpful to me. I am trying to find out some information tritones I've been researching and they are called diminished 5th's or augmented 4th's. I have been reading and reading about them and I understand the basic theory behind them but I don't know how to form chords with these. I have seen some very interesting videos on youtube and they really change how your music sounds. I would appreciate if you could forward me some info on these chords in like the key of c or c#. Thanks God bless you.

Michael,

There are two common kinds of chords that use tritones, dominant chords and diminished chords. So if you take a look at any of the dominant or diminished chords on this site, you'll see tritones in action. Or if you look at any sheet music and you see a dominant chord or diminished chord, you'll see tritones in action.

In a dominant chord, the tritone is formed between the major third of the chord and the minor seventh. For example, in a C7 chord, the major third is E and the minor 7th is Bb. This interval is a flat fifth (i.e., a tritone).

A diminished chord has a tritone between the root of the chord and the flat fifth.

A dominant seventh chord is made up entirely of minor thirds, and two minor thirds make up a tritone.

So a Cdim7 chord has a tritone between the root and fifth (C to Gb), the minor third and diminished 7th (Eb and A) And the inversions of those two, the flat fifth to the root, and the diminished 7th to the minor third (A to Eb).

But all of this theory about tritones is not particularly helpful to playing well. It's more helpful to just start memorizing chord shapes on the piano. That's where my books and my piano chords site come in handy. Once you've memorized the shapes, and trained your ear, you don't need to think about where the tritones are, you'll just know the right sound at the right time - sort of like vocabulary and speech.

One interesting thing with tritones is that they are a tense sound that wants to resolve. If you play a G7 chord:

G, B, F

and then resolve it to a C chord:

G, C, E

you can hear how the tritone between B and F is a tension-filled sound and it wants to resolve to the C chord.