Understand Chords: Tensions--"Sus" and "Add" Chords (Part Five Of A Series)

In our last installment of “Understanding Chords,” we examined extended chords—that is, chords in which thirds are stacked higher and higher, forming chords of the ninth, eleventh and thirteenth. (The last-named chord contains all seven tones of the diatonic scale—conceptually, if not usually in practice.)

So, if extended chords can already contain any possible scale tone, why do musicians complicate things by speaking of “suspended chords,” or “add chords” (which include added tones?)

A definitive answer may not exist, since it must be admitted that in the youth-centered and generally anti-authoritarian world of popular music terminology tends not to be very consistent. People may use terms slightly differently, and disagree about definitions of terms such as “tension” and “extension.” But there are distinct and different contexts which give rise to the terms “suspended chords” and “add chords”—and even specific musical ‘moves’ that accompany them.

Let’s consider examples, beginning with suspended (or “sus”) chords. The whole idea of a “suspension” actually goes back farther into music history than does our modern idea of the chord itself—back, in fact, at least to the fifteenth century.

In those days, harmonies were thought of in terms of the combination of two or more (vocal) lines. Loosely speaking, a harmony was what happened when melodies were sung simultaneously.

But that sounds as if the resulting harmonies were somehow accidental. In truth, the master composers of the day were anything but slipshod in designing their melodies to fit together harmoniously. The art of “counterpoint,” as it came to be called, today fills many books and whole semesters of music school.

Yet the basic idea is simple. The possible harmonic intervals were divided into two basic categories: 1) intervals in which the tones ‘sound together,’ making a stable (“consonant”) sonority, and 2) intervals with “dissonant,” clashing tones which refuse to blend together into a smooth composite.

Here’s a sequence of harmonic intervals—that is, tone pairs sounding simultaneously. Which ones seem smooth and consonant to you? Which clash in bold—or even grating—dissonance?

Your answers may or may not be the same as those of the fifteenth-century masters—your musical ear, after all, has been molded by an additional five centuries of musical experimentation.

But to a fifteenth-century musician, at least, the dissonant intervals were the 2^nd, the 4^th, and the 7^th, shown separately here:

If you agree with those choices, it is very possible that you would also be tempted to call them “ugly” intervals. But part of the genius of the art of counterpoint was the discovery that there were (and are) ways to use these dissonances to create beauties deeper and more satisfying than simple consonances could afford.

One of these was the musical ‘move’ known as the suspension. At the heart of each suspension was a dissonant interval—a 2^nd, 4^th or 7^th. Framing the dissonance in time were a set-up—the “preparation”—and a release, called the “resolution.” Each of these phases of the suspension had to meet certain criteria in order to sound right, but we needn’t concern ourselves here with the details.

Here are examples of three different types of suspensions:

Other variants of the suspension exist, but these are enough to show the origins of the “sus4” and “sus2” chords. Compare the suspended chords below to the suspensions above which gave rise to them.

The ‘sus’ suffix can attach to any chord root. It indicates that the third of the triad is replaced by the suspended tone—either a fourth or a second.

Here is an example showing how a suspended chord works in an actual progression. This is essentially a Classical suspension: notice how the “C” (top note of the chord) is prepared as a note of the F major triad, how it continues as the dissonant fourth in the Gsus4, and then resolves to the “B," the third of the G chord:

Suspended chords can be used in other ways, too. This figure, similar to a well-known riff by Tom Petty, uses both sus2 and sus4 chords to decorate a D major triad. The "F#" (top note of the D major chord) moves stepwise up to "G" and back, then similarly down to "E" before its resolution back to "F#." Listen to the 'crunchy' sus4 and sus2 harmonies that result:

In fact, it’s not necessary today even to resolve a suspended chord at all; you can find many examples of suspended chords used completely independently, with no resolution.

Yet the possibility of a resolution remains the hallmark of a suspended chord. That means obedience to one of the oldest ‘rules’ about suspensions: the tone of resolution should not be present in the dissonant part of the suspension.

(For instance, in Example 4 the “B”--which is the tone to which the dissonant “C” resolves—is not heard until the actual resolution itself. Likewise, the F# which forms the third in the Tom Petty-style lick of Example 5 alternates with the suspended “E” and “G”, but is never heard simultaneously with them.)

But does that mean that you can never create a chord which combines a triad with a 2^nd or a 4^th? No. In fact, the Indigo Girls’ hit, “Closer To Fine,” does just that in an unusual chord heard at the beginning of the chorus:

Here a “D” triad is heard simultaneously with both a 2^nd (E) and a 4^th (G) added to it. The fifth of the triad--"A"--is left out, but the resulting sound is still dense and strongly dissonant. In the song, the chord arrives with no preparation—although it does resolve to an ordinary C major triad. Since the "E" and "G" don't act as suspensions, they are termed "added tones", and the chord becomes "Dadd2add4."

The harmonic idea here is distinctly modern: dissonances don’t need justification; you can insert them wherever you please, and you needn’t bother with resolutions, either, if you prefer not to. The "recipe" for such sonorities is modern, and simple to boot: just begin with a triad and add any tone you like.

In reality, our choices are more limited than the "recipe" makes them sound. Assuming that we stay within the scale, there are only four additional tones available: the 2^nd, 4^th, 6^th and 7^th above the root of the triad. But 7^th chords existed long before the idea of ‘add chords,’ so the 7^th isn't really a new choice here—one could already ‘add’ a 7^th at will anyway. We’ve just seen the addition of 2^nd and 4^th, but the 6^th is a very common ‘add tone’ as well:

Frequently added along with the 6^th is the 9^th. (In this example, the 9th is the "A"--the lowest note in the treble staff. It's called the 9th because "A" is nine notes above the "G" bass.)

You may need to listen pretty carefully to notice the difference between this example and the previous one! It's just a bit more dissonant.

This was a jazz cliché for some time—but like seventh chords, it's not really a new choice, since the 9^th is in effect the same tone as the 2^nd.

(Presumably, the practice off calling it a 9^th, not a 2^nd, arose from the theory of "extended chords"--discussed in Part Four of this series. Extended chords--ninths, elevenths and thirteenths--were being pursued at about the same time in music history.)

Interestingly, the “add 6, add 9” chord can easily result in chord voicings containing stacked fourths, much like some extended chord voicings (also discussed in Part Four of this series.) But perhaps that's a topic for another Hub!

And that’s it! A dollop of music history, a couple of examples, a survey of the available tones (figuring from the root of the chord), and we have a fairly substantial picture of ‘sus’ and ‘add’ chords. (Admittedly, we didn’t consider these chords in minor mode, since doing so would involve a long, detailed case-by-case discussion—and one unlikely to change the big picture much.)

I hope this Hub has given you a few ideas to experiment with in your own music-making. 'Sus' and 'add' chords can definitely increase the harmonic interest and color in your own tunes, or in arrangements. There's an old music adage: “If it sounds good, it IS good!” In that spirit, if using this or that ‘sus chord’ or ‘add chord’ in your music sounds good to you, why then, it probably IS good, too. In other words, don't sweat the theory too much--your ear is your best guide, and the proper spirit to experiment with these chords--as with all musical exploration!--is the spirit of play.

(And if this Hub is a bit shorter than the last couple of “Chords” Hubs, that’s probably all to the good likewise.)

So, happy 'sus' and 'add' chords to you!