How to Get Altered Sounds Using Tritone Substitution
The tritone substitution has been used for almost as long as jazz as being around and although most jazz musicians use it’s often associated with bebop guitar playing.
How to Apply Tritone Substitution
Jazz musicians frequently use substitutions and superimpositions to provide greater harmonic potential for comping and single line soloing.
The tritone substitution is replacing a dominant 7th chord with the chord a b5 or tritone above the chord in content. For example if the dominant 7th chord you want to apply the tritone sub to is G7, the root is G. A b5 or tritone above G is the note Db, so to apply tritone substitute to a G7, replace the G7 with a Db7. The scale diagram below shows how to work out the tritone sub from a G mixolydian scale.
The original dominant 7th chord shares the same guide tone notes with the tritone sub chord, so the main difference is between the two chords is the root, however when a Db7 scale is played, some tastier extensions are produced.
This substitution is particularly useful in cyclic or ii-V-I situations to add aditional crunch to a dominant 7th chord and the new bass note (Db) provides smooth chromatic movement in the bass.
Here are two single line licks that use the tritone substitution technique over the ii-V-I progression.
Tritone Sub Licks
To take this concept further, the ii that belongs to the b5 substitution dominant 7th can be added for further movement and interest. The b5 substitution for G7 is Db7, and the ii minor 7 chord that belongs with Db7 is Ab-7
To play over the Ab-7 — Db7 substitution you can use the Ab melodic minor scale which contains the same notes as the G altered scale providing a nice crunching, just remember to try and resolve smoothly into the I chord, C major 7.
Tritone substitutions can be applied to almost any standard that you’re working on but one song you always hear it used on is the Girl From Ipanema.
The tritone substitution is a great way to quickly get altered sounds into jazz guitar playing, be it simply just using the triad a b5 above the dominant 7th chord in content or using full scales.
How to Practice Tritone Substitution
- Comp through II-V-I’s in all 12 keys, firstly playing the II V I as normal, then add the tritone substitution the second time round
- Write out licks that use the tritone substitution technique and practice them applying them over tunes
The tritone sub is a great device under your fingers to help you get more mileage out of licks and chords when you’re playing jazz that’s often used by the greats. Do you use the tritone substitution in your own playing? What are some substitutions that you like to apply when you’re improvising? Share your thoughts in the comment section below.