Chord Progressions

This is a preview of the educational program A Jazz Improvisation Almanac which is under development for the Outside Shore Music Online School. Feel free to browse this preview and learn what you can from it. For a more completed product, though, check out the original freely browsable jazz textbook, A Jazz Improvisation Primer.

A chord progression is the series of chords used to harmonize a composition. In jazz, improvisation is normally based on the chord progression. The improvisor invents new melodies to fit an existing chord progression. One can improvise more cohesive melodies if one is able to see a progression as a whole rather than as a series of unrelated chords. One can also make more interesting substitutions if one understands the original function of each chord. Understanding the structure of a chord progression can make it easier to remember as well, and it can make it easier to transpose it into another key should the need arise. Therefore, the study and analysis of chord progressions is of interest to many jazz musicians.

In analyzing chord progressions, one rarely tries to consider an entire composition at once. Normally, we look at chord progressions in units that correspond to musical sections such as those we previously referred to as stanzas - the complete statement and development of a single musical idea. It is usually an easy matter to divide a piece into manageable sections. The melody itself often suggests the boundaries. For example, note the way the following composition is divided:

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In a 32 bar AABA form, we can look at the chord progression for the A-section as one unit, and the progression for the B-section as another.

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Once a chord progression has been identified, the first order of business is to identify the key. This is normally obvious in tonal music. The majority of chords will normally be diatonic to the key, and the phrase will often end on the tonic:

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A phrase may end on the dominant, in which case it will clearly sound as if it is ready to resolve to a tonic to begin the next phrase:

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Sometimes a phrase will resolve first to the tonic, or a substitute for the tonic, but then goes into a short sequence of chords that ends on the dominant in order to lead to the next phrase. This is known as a turnaround. A particularly common turnaround is the iii-vi-ii-V:

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The ending of a phrase may contain a modulation to another key. In such cases, usually the original tonic is reached shortly before the end of the phrase, and then there is a short turnaround to the new tonic or its dominant:

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In a 32-bar AABA form, the progression for the A section often differs from the first to the second phrase; the first phrase typically ends on a V chord, whereas the second phrase usually resolves to the I, possibly followed by a modulation to the bridge, which is often in a different key, such as the subdominant. The bridge usually modulates back to the original key for the final A-section.

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When analyzing a given chord progression, ideally one tries to understand the function of each chord in it. This is not necessarily as difficult or complex a task as you might think. Often, an entire chord progression can be seen in terms of ii-V-I sequences and modulations. For example, consider the following chord progression:

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Look for places where the roots move upward by fourth. Also, since tritone substitution turns this into motion downward by half step, look for this pattern as well. In the above progression, we find the following:

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Note then that several of these resolutions can be seen as ii-V-I sequences, or perhaps just ii-V or V-I, if one considers each dominant seventh chord to be a V chord in some key:

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One should try to determine the boundaries between key centers suggested by these sequences within a progression. Note that some of the modulations may be to closely related keys while others may be to more distant keys.

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Often, many of the remaining unclassified chords turn out to be diatonic to their respective keys:

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Any remaining non-diatonic chords can then be analyzed individually:

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Diminished seventh chords can be tricky, because these chords are symmetric. This means that a diminished seventh chord built on any note of the original chord yields exactly the same result. For example, Bdim7 consists of B, D, F, and Ab, and the Bdim7, Ddim7, Fdim7, and Abdim7 chords all consist of the same four notes:

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Thus when you see a diminished chord in a progression, any of the other related diminished chords may be just as appropriate. If a diminished chord appears to be irregular, try replacing it with any of the other related diminished chords. You are likely to find it is a secondary diminished chord, substituting for a dominant seventh chord. For example, in the progression Ddim7-Am, the Ddim7 can be considered as G#dim7, the viio7 of the key of A harmonic minor, and it is therefore substituting for the V7 chord, E7:

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This is discussed in more detail in the section on the WH diminished scale, which is the scale associated with a diminished seventh chord.

Here is complete example of a chord progression that has analyzed for you. Study it carefully.

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Once one has analyzed a progression in this fashion one can make better decisions about improvising over the progression. Some of the various options available to the improvisor are described at length in following chapters.

If a progression does not seem to lend itself to this type of analysis, one should consider the possibility that the progression is not in fact tonal. Non-tonal chord progressions are discussed in the next section.

Copyright 2000 Outside Shore Music
Authored by Marc Sabatella

Chord Progressions