Barbershop Arranging — Part 2: The Circle of Fifths
A framework for harmonization based on tension and release
This is Part 2 of a 10-part series on barbershop arranging. The full guide is here.
In the previous chapter, we presented the acoustic principles that arrangers and ensembles should have in mind to maximize the perceptual synergy between voices. We finished with a bit of a cliffhanger, claiming that the four-part Barbershop chord is important not only because of its rich harmonic amplification, but also because of its pivotal importance to harmonic motion in Western tonal music since the 1600s. In this post, we’ll explore and defend that claim.
To the extent that the last article focused on vertical concerns—chords, tuning, harmonic amplification, and so forth—this post will give us a framework for horizontal concerns—namely, how to choose chords that flow intuitively from left to right over the course of a musical phrase. In the post after this one, we’ll see that the early steps of any arranging process hinge far more on the horizontal concerns that we’re about to discuss.
The Barbershop chord, revisited
Two intervals, not four notes
Recall that the barbershop chord is comprised of scale degrees 1, 3, 5, and flat-7. We’ll inch toward the Circle of Fifths by rethinking this chord architecture not as four stacked pitches, but as two overlapping intervals.
The Barbershop chord is a beautiful balance of stability and instability in one chord, a veritable marriage of harmonic yin and yang. At the base, we find a powerful Perfect 5th between the root and fifth, lending the chord its structure. And woven within that, we find the irritable, mossy growth of a tritone.
To the extent that a Major Triad proclaims stability, the Barbershop Chord longs for something more. The pitches and harmonics of the Perfect 5th align in a beautiful acoustic friendship, one that pleases the ears, excites the mind, and puts the soul at ease.
But the pitches and harmonics of the tritone gnaw at the ears with a paradoxical dissonance: at once devilishly self-satisfied yet inwardly hellbent on finding the baptism of future peace. The tritone is instability embodied, the musical equivalent of a jet’s jostling controls as it nears Mach 1. The instability can add conflict and meaning to our journey, but at some point, the ear wants it — needs it — to resolve.
Here is a deconstruction of the chord in a slightly different spelling from that shown above, with the Tritone stacked completely atop the Perfect 5th. The Perfect 5th sounds first, followed by the Tritone, then the full chord. Note that both intervals are crucial to defining the character of the chord:
Our objective as arrangers is to leverage this tension to assign chords to melody notes in an intuitive sequence. How might we do this? Where does the tension in the Barbershop chord actually “want” to go? To answer this question, let’s reflect on one of the aliases of this illustrious chord: the “Dominant 7.”
The Dominant 7
Just as velocity in the universe is always relative to some reference frame (“my car is going 60 miles per hour relative to the road, but 2 miles per hour relative to the car in the lane next to me”), scale-degree chord spelling in music is always relative to some reference key. A Barbershop chord built on a C Major triad will consist of C, E, G, and Bb; in C Major, these pitches correspond to scale degrees 1, 3, 5, and flat-7.
What if we change our reference frame? Relative to G Major, say, these same absolute pitches would correspond to scale degrees 4, 6, 1, and flat-3 (C is a Perfect 4th above G, E a Major 6th, etc.). In E Major, these pitches would correspond to scale degrees flat-6, 1, flat-3, and flat-5 — fairly clumsy. But in F Major, it so happens that these pitches can be expressed without any sharp or flat modifiers at all: as 5, 7, 2, and 4. This means that C7 is more cleanly described as “belonging” to F Major rather than C Major (to say nothing of G Major or E Major)!
Indeed, C Major and F Major are very “similar” in some sense: all we have to do is flat the seventh of the C Major scale, and suddenly we have precisely the pitches that comprise the F Major scale.
In the reference frame of F Major, C as scale degree 5 is so important next to F that it is called the “dominant” of the scale, hence the C7 chord is the “dominant seventh” in F Major.
Every major scale has its own unique Dominant 7 chord built on scale degrees 5, 7, 2, and 4. Thinking again in terms of two intervals, the Perfect 5th is between between scale degrees 5 and 2 (the C and G in a C7 chord), and the Tritone is between scale degrees 4 and 7 (the Bb and E in a C7 chord).
Tritone Resolution
Let us now return to our original question: if the Tritone within the Dominant 7 chord wants to resolve, where does it want to go?
Simply put, the tritone finds stability by resolving inward just slightly: the 7 ascending to scale degree 1, and the 4 relaxing down to scale degree 3, forming a stable Major Third in the new reference key. Thus, the tense C7 chord from our previous example finds solace in its most similar new reference key, F Major!
This resolution is so engrained in Western ears that you may not even realize how intuitive it is. Here’s what it sounds like:
Again, this progression is intuitive precisely because it finds stability while maintaining a near-identical harmonic sonority with that of our old reference key—recall that we needed only to flat the seventh to transport the ear to the new reference key. The result is the canonically satisfying dominant-to-tonic progression that has stood the test of time since at least the days of Bach.
For completeness, here’s the resolution of the full C7 chord into F:
That was a lot of content about one chord, but the key takeaways are:
- Barbershop chords consist of a stable Perfect 5th and an unstable Tritone.
- The instability of the Tritone component is what makes the Barbershop chord want to resolve.
- The most intuitive place to resolve, harmonically, is to the key that contains the flat seventh innately, which happens to be the key in which the Barbershop chord is built on scale degree 5 (the “dominant”).
The Circle of Fifths
Finding the pattern
We’ve just seen that we can stack a flat seventh onto a C Major triad to achieve a tension-ridden C7 chord, and that this chord will “want” to resolve its Tritone toward a new Major Triad built on F.
So…what if we stack a flat seventh onto the new F Major triad? We’d get an F7 chord that wants to resolve to a new key that is now “similar” to F, in which F’s flat-7 is now scale degree 4. That key is none other than Bb, in which F is the dominant!
We can continue this pattern endlessly:
- Reach a Major Triad in key X.
- Add the flat-7 to introduce tension.
- Resolve to the key in which X is the dominant.
- Repeat.
This pattern lets us slowly coax the ear to keys less and less similar to the original key. However, the set of keys is finite: recall there are only 12. Eventually — miraculously — from some distant inflection point, the pattern starts to circle back to keys that are increasingly similar to the original key, until we finally arrive back at the original key itself!
Naming the pattern
All we’re doing is repeatedly introducing tension and then releasing it in the way that will least surprise the ear. We call this pattern the Circle of Fifths, since each 7 chord along the way becomes the dominant chord built on scale degree 5 of its new key. The intuitive motion of the Circle of Fifths has made it the foundation of harmonic movement in Western tonal music since the 1600s, when composers first experimented with and formalized it.
Progressions along the Circle abide by the simple concept of tension and release: the dominant ever longing for its tonic, the Tritone ever yearning toward its Triad. The Circle of Fifths is a never-ending cycle based on the tendency of instability to motivate movement toward a better place.
Below is a video of a complete revolution around the circle. Each resolution is so intuitive that you hardly notice the gradual change in keys at all. The magic is that by the time you’ve made six or seven jumps, you’ve arrived in a new key that sounds nothing like the original and would in fact completely clash with it—yet after 12 jumps, you arrive right back where you started!
Using the pattern
The Circle of Fifths appears everywhere in the works of the great composers. The main idea with the Circle of Fifths is that music tends to start at home, go on a little adventure, and then find its way back intuitively. Like the literary Hero’s Journey, conflict will wrest the protagonist from a place of stability through trying times of tension, until the protagonist overcomes all and returns home with a satisfying sense of accomplishment.
Concretely, the Circle of Fifths describes how a composer can progress from the original key to any other, or the original Major triad to any other, and then follow the chords on the circle to guide the ear intuitively back “home” again. The composer need simply jump from the original key to an arbitrary place on the circle, and then follow the dominant-to-tonic chords along the circle’s circumference until the harmony has arrived back at the starting key.
The only other stipulation is that the arranger must make the chords in this journey fit with the notes in the melody. This can be quite a puzzle and can easily lead to dead ends that require backtracking and trial and error. Some melodies of course make this easier than others. We’ll focus on this in the next post when we arrange a sample melody.
Visualizing the pattern
As a concept, the Circle of Fifths is crucial to our objective of understanding intuitive harmonic motion. As a graphic, it is typically optimized for a different purpose, such that most Circle of Fifths graphics are difficult to interpret.
Consider the visualization below from Wikipedia. This is canonical representation of the Circle of Fifths, with visual cues geared far more toward demonstrating the relationship amongst key signatures than anything to do with chord progressions. We can see, for instance, that C Major has no sharps or flats, F Major has one flat (on scale degree 4, the flat-7 relative to C Major), Bb Major has two flats, and so forth. This topic is helpful in its own right, but it’s not what we care about at the moment.
In Wikipedia’s visualization as in most others, there are no cues whatsoever about how chords should progress. We simply have to know a priori that moving counter-clockwise along the circumference will give us the chord-progression “cheat sheet” we’re looking for. The typical Circle of Fifths graphic conforms to the familiar visual metaphor of a clock, but it has time ticking in the wrong direction.
Effective data visualization should streamline cognition. We can design a graphic that accomplishes this far more effectively by making the following adjustments: (1) reflecting the circle about the Y axis so that time moves in a metaphorically consistent clockwise direction, (2) removing visual noise about key signatures, and (3) providing concise usage instructions.
Here is a 🌟 redesigned Circle of Fifths visualization 🌟 that hopefully explains far more clearly how chords should progress around the circle.
The Barbershop approach
In classical music, we might employ a variety of seventh chords yet to be discussed in this series, or dwell in a new key “area” for a few measures before introducing the flat-7 and moving on to the next key.
In barbershop, far more of the chords in the Circle of Fifths journey are pure Dominant 7 chords, which keeps both the harmonic amplification and the harmonic tension intact. Barbershop in its classic form typically resolves not to a new Major Triad, but to a new Dominant 7 that is already itching to move on. Here’s what this “warp speed” version of the Circle of Fifths sounds like:
Following is an example of a Circle of Fifths progression in an arrangement of the (rather lyrically antiquated) 1920s standard, Five Foot Two. We jump from the original key of Ab to C7, and then walk the circumference of the circle back to Ab, via C7 → F7 → Bb7 → Eb7 → Ab.
Although classical music tends to feature a lesser predominance Dominant 7 chords, classical composers have been known to enjoy warp-speed Dominant 7 chords, too. In fact, in Franz Liszt’s beautiful Liebestraum №3 from 1850, the composer employs the very same chords as in Five Foot Two!
The Barbershop Harmony Society has posted a wonderful presentation about the Circle of Fifths by Dave Stevens, titled “What are we trying to preserve?”. In a succinct eight-minute demonstration, Stevens explains how the Circle of Fifths appears everywhere in early popular music. He even notes the similarity between Liebestraum and Five Foot Two:
Reflection
This Circle of Fifths requirement may sound restrictive at first glance. Wouldn’t all songs start to sound the same if they always followed the same chord progression — or were modified to do so by a hard-headed arranger? To an extent, yes. But most songs prior to the 1950s nevertheless relied extensively on Circle of Fifths progressions and lend themselves naturally to the barbershop style. And many songs since the 1950s have clung just as earnestly to a rigid progression of a different stripe: the I-vi-IV-V:
Still, barbershop has evolved over the decades to accept all manner of melodies into its hallowed harmonic language. Arrangers are constantly pushing themselves to honor the roots of the barbershop style while simultaneously coaxing it into new harmonic territory. But always at the core of it all, is the Circle of Fifths.
Now that we’ve covered the fundamentals, it’s time to arrange our first melody. See you in the next post.
Next: Part 3: Arranging a Simple Melody
Full guide: Barbershop Arranging: A Modern Guide
