Space chords to mimic the spacing of the harmonic series: use large, wide intervals in lower registers, and smaller, closer intervals in upper registers.

Extensions should be voiced in the higher voices.

If you double a note, usually double either the bass or the root of the chord.

Omitting the fifth of the chord is almost always perfectly acceptable.

Use smooth or "lazy" voice leading: move each voice as little as possible between chords to achieve a smooth, easy-to-perform sound. A common smooth voice-leading schema in jazz is to lead from the third of one chord to the seventh of the next, while another line connects the ninth of the first chord to the thirteenth of the second chord.

Guidelines can be ignored, but this should be a conscious and deliberate decision to achieve a desired effect.

So far in this unit, you have written chords in an unvoiced format. While unvoiced chords are useful for conceptualizing harmony, you would not want to perform these tall stacks of thirds. This chapter will discuss how to voice these harmonies in a manner that is idiomatic to jazz. We will focus on voicings that play the root in the left hand at all times so that the harmony is always clear, although in performance, the root is often omitted (because it is covered by the bassist).

Spacing

The common spacing of chord members in musical textures has much to do with acoustics. We discuss pitches as specific frequencies—for example, A 440, the note to which most orchestras tune, refers to pitch A that has a frequency of 440 Hertz (Hz). But in fact, when an acoustic instrument plays A 440, 440 Hz is only one of the frequencies that is activated at that moment in time. The instrument will also activate the harmonics above that pitch, because the vibrating body causes other, shorter vibrations to occur simultaneously. These harmonics are part of what create an instrument's unique timbre.

The harmonic series is approximated in Example 1. The notes of the harmonic series do not conform to twelve-tone equal temperament, but they have been notated at the nearest pitch for the sake of convenience.

[](https://viva.pressbooks.pub/app/uploads/sites/12/2019/08/harmonic-series_0001.png) Example 1. The harmonic series, as approximated in notation.

Note that the pitches are spaced widely apart in the lower harmonics, but become closer and closer together in the upper harmonics: the distance between partials 1 and 2 is an octave, but beginning at partial 13, the distance between subsequent partials is only a half step.

In general, spacing in music approximates the harmonic series: notes are further apart in lower registers, and closer together in higher registers. Putting notes close together in a low register tends to sound muddy and dissonant, even when the chords are consonant. When notes are spaced wide apart in the upper registers, the upper note will sound quite prominent and isolated in the texture (though this can sometimes be a good thing).

Remember that the bass line is probably played by the upright bass—and this instrument sounds an octave lower than written, so its lowest note is an E1, three Es below middle C. It's normal for the bass to be in a register very much apart from the rest of the ensemble.

Chord extensions should be left in the upper registers of the texture. Recall that this is reflected in their names—a thirteenth is not the same as a sixth in jazz harmony. Voice the thirteenth somewhere above the seventh of the chord; otherwise, it will sound like the sixth.

Doubling

In general, a safe note to double is the bass note. Most often, the bass note is a relatively stable member of the chord. Because it's the foundation of the texture, it sounds good to double the bass.

Another good option is to double the root of the chord, even if it is not in the bass. The root note, like the bass, is typically a stable tone, and will strengthen the chord when doubled.

Omitting Notes

Jazz harmonies often contain many notes, thanks to the common practice of extending the harmonies. It often wouldn’t be desirable for all these notes to be given equal weight in the voicing, so it’s common to omit some notes when voicing these extended harmonies.

The most common note to omit is the fifth of the chord. Because the fifth is an early pitch in the harmonic series (partial 3), it tends to strengthen the root of the chord without adding much character on its own. Listen and compare the various chords in Example 2, and notice that removing the fifth does very little to alter the overall sound of the chord, whereas omitting the seventh or root alters the sound substantially!

Example 2. Omitting the fifth is common, as it does not substantially alter the sound. The seventh and root are hardly ever omitted.

Omitting the root runs the risk of destabilizing the entire chord. However, if there is a bass player in the performing ensemble, you may deliberately omit the root in the other voices. The bassist will typically provide the root of the harmony and ensure that the chord sounds stable. The last chord in Example 2, then, would sound just fine if a bassist were playing a G below that voicing.

When dealing with extended chords, it becomes possible or desirable to omit other members of the chord besides the fifth, but it is difficult to generalize here. Usually, omitting tones is done to avoid excessive dissonance with other important chord members.

Smooth Voice Leading

We have been discussing harmonies as vertical entities so far: as a stack of notes that go bottom-to-top on the page. Vertical thinking is used a lot in music theory and by pianists and guitarists, but for almost everyone else, music is experienced horizontally: as a sequence of notes in time. It's important for musicians to be able to think of music both vertically and horizontally through voice leading.

Voice leading in jazz and many other styles should generally be smooth—