Lesson 7: The Tritone Blues
In this lesson we investigate the properties of the nefarious tritone interval. As I explain in the video, the tritone can be found lurking within the 7th chord shapes that we already know. If we strip away the other notes in the chord we are left with just the 3rd and the flat 7th, and these notes - known as essential chord tones - are all we need to give us a 7th chord sound. So rather than playing big 5 or 6 note 7th chord voicings, we have the option of just using this tritone, to give us a minimal, funky kind of sound.
It may be helpful to visualise these tritones as a part of the bigger parent 7th chord voicing, so you always know what chord it is you're playing and where its root note lies.
Below is a diagram showing the I IV and V chords and their related tritones in the key of C.
And here is a transcription of the piece I play. Download here. Rhythmically it's quite simple: a four bar repeating rhythm played mostly on the downbeats, with a swung upbeat in the third bar. Keep your strumming hand moving throughout, perhaps adding in a few scratches to help with the groove. Use all down strokes with the pick except for on the upbeat where you can use an upstroke (or you could play this with a downstroke as well, for a nice consistency in tone throughout the piece). Use whatever fingering you find comfortable. Fingers 1 and 2, 1 and 3, or 2 and 3 all work well.
A few other things to try
- Play the piece in other keys
- Come up with some different rhythms of your own
- Try finding the tritone shapes on other string sets