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Virtual upper-structures

Arpeggiated substitutions in functional harmony


The idea of chord substitution is central to modern jazz improvisation, and there are many different approaches to this subject, by many different musicians. Especially well-known is the work of the American saxophonist Jerry Bergonzi. This project is my own approach, where I describe the substitution shape and demonstrate techniques for the conceptualisation of the substitution "on the hoof". I'm currently working on expanding this much further, and will give many more examples, but as yet I haven't made much of an effort to make this user-friendly. As it stands, you'll need more than a passing familiarity with jazz theory for this to work for you in any practical way, but I think it can be helpful if you are looking for a way to expand your improvising over familiar chord sequences.

I am always happy to hear from people who have suggestions. Send me a mail.

When playing a line over a chord sequence it is possible to employ three- or four-note arpeggios which belong to the same harmonic area as the original chord, instead of always thinking in terms of scales and modes. This is a way to introduce controlled dissonance or even bitonality to a solo, while never playing completely outside the function of the harmony.

These secondary figures are often derived as extensions of the original chord. It is important to remember that these new labels on the harmonic event are not themselves harmonic events in the conventional sense, and it is therefore meaningless to treat them as such. They are simply pools of notes which can be arpeggiated in various ways to maintain a distance from the underlying chord sequence. They can also be used as chord substitutions by a guitarist or pianist where the bass follows the original changes.

In the first table I give diatonic substitutions, taken from various degrees of the original chords without altering the basic tonality. Since the fourth of the major chord at I is so unstable, it is assumed that it is preferable to use a lydian mode as default.

2Em7Am7D7mixo -1

This second table deals with the altered progression, where the V chord has a strong b9:

3Fmaj7BdimEm7Functional phrygian
5Am7Gmaj7Functional mixolydian
6E7Am7Relative minor
7Cmaj7Bm7functional +2

In the third table are possible substitions for a minor II-V-I, where the I chord is melodic minor.


Certain of these strings are easier to conceptualise than others, and some are so at odds with the harmony that functionality is almost completely lost. To make this information of practical use it is important to choose which ones work best, and also to mix substitutions from different degrees when reharmonising a II-V. Especially effective are those which share a virtual bass note, or those which appear to move in parallel - in other words, those which have a kind of integrity.

Here is a list of some of those I feel work best for the major II-V-I ( a combination of the possibilities from the first two tables). These are grouped according the to the harmonic starting-point at II, and for the most part arranged thereafter as chromatically as possible.

alt 1aFmaj7Em7chromatic U.S.
alt 1bFmaj7E7Am6Relative minor, VI-V-I
alt 2aAm7Ab min-maj7Gmaj7chromatic resolution,
fifth above
alt 2bAm7Abm6Am6Hovering minor sixths
alt 3Cmaj7Bmaj7#5Bm7High chromatic

Let us look at a practical application of these ideas. Taking the beginning of “Giant Steps”, which contains three major key centres, I outline the five alternate harmonic schemes.

alt 1aD#m7Bm7AbøGm7
alt 1bG#m6B7Em6G7Cm6
alt 2aF#maj7Eb min-maj7Dmaj7B min-maj7Bbmaj7
alt 2bG#m6Ebm6Em6Bm6Cm6
alt 3A#m7F#maj7#5F#m7Dmaj7#5Dm7

Am currently transferring this work to HTML. More to come.