What is Reharmonisation - Mark Levine on Tritone Substitution

Below is an excerpt from Mark Levine's "The Jazz Piano Book".  It shows an example of a kind of chord substitution called "tritone substitution".

I feel it is important to examine these reharmonisation techniques as doing so will lead to a better understanding of what may or may not work within the context of this reharmonisation project.  

Above is an example of chord substitution (or reharmonisation) in use.  This excerpt was selected to provide visual evidence for the preparation of the project.

In the above photo, taken from Mark Levine's book, we can see two different chord sequences within Figure 6-3.  The first three chords represent a basic ii-V-I chord sequence, a chord sequence which was explored in depth within the project.  The second three chords show the same sequence, though this time it's been reharmonised with a basic tritone substitution.  We can see that the G7 chord has been replaced by a Db7 chord.  This type of reharmonisation makes the chord sequence sound more dissonant and modern, compared to the classic sound of the original chord sequence.

The figure below it, figure 6-5 shows the notes of both chords, showing the contrast (and similarities) between the two chords.  By studying excerpts like this and practically applying them at an instrument, a better understanding of the inner workings and results of reharmonisation can be gained.  By studying various similar textbooks and sheets of music, as well as through listening to them in use, my understanding of reharmonisation and ability to create the ruleset within the project was expanded greatly in the few months that the bulk of the project was carried out in.

J

References

Levine, Mark. The Jazz Piano Book. Petaluma, CA: Sher Music Co., 1989. Print.