Concepts of Harmony in Jazz

In discussing the application of harmony in jazz composition, it's important to consider the major ways in which the music differs from its European counterpart. With only minimal analysis, one can discover that the chordal palette of jazz music tends to be far broader than classical music. Even composers known for their use of extended chords – most notably, Claude Debussy – use them sparingly: the notion that his impressionistic style is the product of frequent use of extended chords is decidedly false. Yet at times, the works of even relatively early composers such as Haydn and Mozart seem to offer a wider spectrum of harmonic colors than the typical jazz standard. In order to understand this – and further one's own compositional abilities – we'll take a short look at some specific differences in these musics.

In the classical conception, chords generally occur as a combination of independent melodic lines, undoubtedly a byproduct of the music's choral roots. While pieces by composers such as Mozart and Schubert tend to employ block chords frequently, more often than not, this music has a substantial level of polyphonic activity. The advantage of this style comes in the drastic effects voice-leading can have on a harmonic progression. If you've ever taken a theory class, you'll be at least somewhat familiar with the concept of voice-leading: in short, a way of writing multiple melodic lines that flow between many chords smoothly. Creative approaches to this technique can turn a rather simple harmonic progression into a monumental event. This introductory passage of Shostakovich's Prelude in F Major from Op. 87 demonstrates how one can turn a rather tame – and by that point, old fashioned – modal mixture into a unique musical event.



What can be learned from this is that the effect generated by a chord does not arise simply from the chords quality, but the manner in which that chord was approached. While one can reply to all of this by stating the use of polyphony in Dixieland jazz, they'd be (probably knowingly) pointing out the exception to the rule. In general, improvised music doesn't lend itself towards complex voice-leading: by the time one begins to write enough of the material on paper, the spontaneous feel of the music starts to disappear.

Another difference – one that is an outgrowth of the last – is the classical composer's tendency to invert chords to create more fluid passages of music. In fact, the conception that the inversions of a single chord belong to a single family is fairly modern: composers as late as J.S. Bach considered the three inversions of a triad to be unique chords with separate functions. And indeed, every inversion of any chord provides a unique sound which the experienced composer can use to their advantage. If you'd like an easy example, go sit down at the keyboard and play G7 followed by G7/F: while both chords technically resolve to C Major, they sound surprisingly different. Yet in jazz, chord inversions rarely occur. Almost every standard has every chord written in root position; if an inversion does appear, 95% of the time it will be the result of a dominant pedal, which in many ways, is an entirely different compositional technique. The role of the bass player in the jazz rhythm section easily explains this difference. Written bass lines tend to be uncommon in the jazz repertoire, as, like any writing, they can easily impede the improvisatory feel of the music. That's not to say inversions don't occur – many bass players probably play inversions without the rest of the band really realizing it – but if a composer gives a bassist a long series of inverted chords, the variety of possible bass lines quickly dwindles.

The innovations in jazz writing that took place in the 60's show a conscious effort to circumvent these limitations. Chords expanded far beyond their typical four-note voicings, the general pace of the harmonic rhythm found in a piece slowed down, and non-functional chord progressions – that is, sequences that operated outside of the typical diatonic model – became standard. The final product was the shifting modal music of Wayne Shorter (which I've already touched upon a few months ago in this blog). And by and large, this model remains the standard for jazz composition. In this conception, a wide chordal vocabulary is necessary to approach writing. Starting with the next entry, we'll investigate some of the chords that came into use, as well as some lesser-used chords.