II  V  I progression, part two

 There are more possibilities to alter the pure II-V-I progression besides or in lieu of adding notes to the chords. A common concept of jazz harmony is reharmonization of chords. In practice, this means that a given chord can be substituted for another, following certain traditional rules .

  II-V-I is no exception, and the common way to reharmonize this progression is to take out the V7 and instead insert IIb7b5, especially when the b5 note of the new chord is used in the melody line. For example, in a Dm7-G7-Cmaj7 the G7 chord can be substituted with Db7b5. The reason this procedure is acceptable are the common notes of V7 and ii7b5 chords, in our case three out of four notes of G7 (GBDF) are also featured in Db7b5 (Db, F, Abb=G, Cb=B). Noticeably, the only non-common note is the D, which becomes Db in the substituted chord. This is what makes the progression interesting  in this way it is possible to play a smoother chromatic bass line along the whole progression (D-Db-C) and avoid the original fifth interval skips (D-G-C). The skips, of course, are not bad  per se but sometimes beg for variation.

  Below is an example of the variation examplified above. Notice also that the new chord is available for added notes (as described in previous part), which can be chosen so that they are common with the added notes of the original V chord (e.g. G13-to-Db7#9).

 Another chord we mentioned, even if not a part of II-V-I, but sometimes in a progression of fifths, is the minor subdominant chord. Usually it functions as a replacement or a complement to the major subdominant chord, and is followed by III, V, or I. The minor subdominant can however be substituted by a dominant ninth chord with root a fifth lower than the subdominant root. Example: in a Gmaj7-Gmin-Dmaj7 progression, a C9 chord can replace or follow the Gmin. As so often the case with reharmonization, the substituted chord and the new chord have some common notes, and some new notes (see for yourself!). Here s the note example:

Home  Theory  Science  Sheet Music  E-zine  Contact us