Barbershop Arranging — Part 3: Arranging a Simple Melody

Using the Circle of Fifths to guide harmonic choices in practice

This is Part 3 of a 10-part series on barbershop arranging. The full guide is here.

Introduction

Now that we’ve covered the science behind barbershop and the Circle of Fifths, I’d like to introduce the art of barbershop arranging, initially with maximal constraints to show how the method works at a fundamental level. In the coming chapters, we’ll introduce more complex melodies and broaden our toolset to accommodate the challenges they introduce. Finally, we’ll fling the doors open and re-imagine some of our previous harmonic choices if we allow for some more recent, more progressive additions to barbershop’s chord vocabulary.

Pre-Lesson: Roman-numeral chord names

Let’s introduce a chord-notation syntax that will make some of the following discussions easier to reason about. In the last chapter, we talked about scale degrees for pitches in a major scale: 1 being the “tonic,” the pitch after which the scale is named, followed by 2 through 7, before we return to 1 again. The idea is that no matter which key you’re in, the function of and relative distance between scale degrees is always the same, such that you always have an idea of what the interval between two particular scale degrees will sound like (e.g., the interval between 1 and 3 is always a happy major third).

Roman numeral analysis lets us do a similar thing with chords. In Roman numeral analysis, we name each chord using a Roman numeral corresponding to the scale degree of the chord’s root. Major chords are named using an uppercase numeral (I, IV, V…), minor chords are named using a lowercase numeral (ii, iii, vi, ), and we can add decorations to capture additional pitches or modified pitches as needed.

In a major scale, the triads built on scale degrees 1, 4, and 5 will be major (a major third beneath a minor third); we thus name them I, IV, and V. The triads built on scale degrees 2, 3, and 6 will be minor (a minor third beneath a major third), earning them the names ii, iii, and vi. Finally the triad built on scale degree 7 is diminished (a minor third beneath a minor third), which we indicate with a small, superscript circle after a lowercase numeral: vii°.

Here’s what all of them look like on a keyboard:

The Roman-numeral names of triads built on various scale degrees in C Major.

And here’s what they sound like in sequence:

We can modify chords at will to be major or minor by “borrowing” pitches from outside the major scale. For instance, we can promote a ii chord to a II chord—a major chord built on scale degree 2—by sharping the 4 just for that chord. By the same token, we can demote major chords to minor chords: a I chord becomes a i chord if we simply flat the 3 in that chord. We can use chord roots that are not contained in the scale, by pre-pending a # or b to the roman numeral: a major triad built on flat-7 is thus bVII.

Seventh chords are fair game as well. We can name Dominant 7 chords (a major triad with an added minor 7) by simply adding a 7 to the numeral: I7, IV7, V7. There are other types of seventh chords, but we’ll ignore them for now.

Right away, this gives us a new way to look at the Circle of Fifths. Instead of thinking about moving between specific named keys, we can now think about moving between specific chords relative to the current scale. If we’re in C Major, we can capture a G7 → C progression as V7 → I. Further, we can capture a D7 → G7 → I progression as II7 → V7 → I.

For the masochistic reader, this means that, relative to the current key, we can capture a full revolution of the Circle of Fifths as follows:

I7 → IV7 → bVII7 → bIII7 → bVI7 → bII7 → bV7 (or #IV7) → VII7 → III7 → VI7 → II7 → V7 → I

With this out of the way, we can now move into the topic of the day: arranging a simple melody in the barbershop style!

🎵 If you would like to play along as you read, feel free to use my web piano, Keyano, which will name intervals and chords as you play them on your computer keyboard.

A functional mindset

A barbershop arranger must be an architect of tension. The fundamental goal is to arrange a given melody in a manner that introduces tension quickly and then follows it on an intuitive path of resolution back to a place of stability—over and over again.

As an initial mental model, think of a basic barbershop arrangement as a function with two inputs:

1. The melody, the sequence of pitches and lyrics in the original melody,
2. The chords used in the original song,

…and one, multi-faceted output: an arrangement that is at once:

1. Intuitive, following the Circle of Fifths as rigorously as possible,
2. Singable, staying in each singer’s comfortable range and minimizing the distance each singer must “jump” between chords, and
3. Appropriate, honoring the sound and feel of the original song as much as possible.

Constraints

To narrow the space of possibilities for our initial example, we’ll impose the following constraints:

1. Every melody pitch must be harmonized by some chord.
2. Every chord we select must include its associated melody pitch in its makeup (e.g., we can’t harmonize a D# using a C Major Triad, because a C Major Triad does not include D#, but we could harmonize a C, E, or G).
3. The I chord may progress to any other chord, including itself.
4. Other chords must progress according to the Circle of Fifths.
5. The song must end on a I chord.

Let’s represent the chord-progression constraints — #3, #4, and #5 — graphically. In the visualization below, each circle represents a chord, and the arrows indicate how we’re permitted to move between chords. Note that each chord has a self-referential arrow indicating the chord can progress to itself.

Take 1: Arranging with V7 and I

Since we’ll be working on a simple example, we’ll consider only two chords for now: I and its immediate predecessor on the Circle of Fifths, V7.

The graphic below captures the full set of progression rules we care about. The gray dashed lines indicate that we could in theory go elsewhere from I, but that we’ll ignore those other destinations for the moment. The double circle around I means that we must end there in order to “accept” our harmonization and consider it a success, per Constraint #5.

A visualization of the constraints we’ll impose on chord progressions, initially. (Generated at http://madebyevan.com/fsm/)

Note: In computer science, this visualization is called a Finite State Machine, and it’s actually quite a useful tool for modeling computation in general.

Finding a chord progression

This is starting to look a lot like an optimization problem — or at the very least, a puzzle! Let’s take a crack at it by hand on a simple example.

We’ll use Mary Had a Little Lamb set in C Major. In this key, a C Major triad will be synonymous with a I chord, and G7 will be synonymous with a V7 chord. These are the only two chords we’ll consider, per our diagram above.

Here’s a sample of the first verse and some chords that a might typically accompany it:

The typical chords used to harmonize “Mary Had a Little Lamb.”

Before we do anything, we should look at the original chord progression and see how well it satisfies our chord-progression constraints. In this case, we’re in luck! The chords move as follows, perfectly in line with our rules:

I → V7 → I → I → V7 → I

This means that at a high level, our song is going to fit well into our chord progression constraints.

Next, let’s peruse the melody pitches to see if the suggested chords fit with each melody note. In this case, we observe that most pitches work fine with the listed chords, but a few don’t fit:

Some melody pitches don’t fit the suggested chords.

Here’s a keyboard view of the two offending phrases, “Ma-ry had a” and “fleece was white as,” with the the offending pitches in red (ignore the specific chord inversions used here, as they’re chosen only for visual convenience):

A keyboard view of the melody pitches that don’t fit into the chords harmonizing them. Offending pitches are represented in red.

The fixes in this case are fairly straightforward. Taking the first phrase, if we go to G7 on “-ry,” then we’re able to progress back to C on “had” per our progression rules. Likewise, we can transition right back to G7 on “a,” and then back to C on “lit-” in the second measure. We can employ these same tactics on the repeat of this phrase in the second system.

The second offending phrase is just as easily fixed. We can go from G7 on “fleece was” back to C on “white,” before returning to G7 on “as” — all of which obey the rules in our progression diagram.

Here is the updated harmonization:

We can re-harmonize troublesome melody pitches in a second pass.

With that, we’ve found a basic progression! Here’s what it sounds like:

Before we tie a bow on our chord progression, we should make one final adjustment to make it truly sound like barbershop. Currently, the end of the first phrase — the repeat of “little lamb” in the fourth measure — ends on a I chord that doesn’t particularly want to go anywhere.

Instead, we can switch to a V7 on that repeated “lamb” to end the phrase with an exciting tension that will urge the song to continue. (The singers are also likely to breathe at this spot, and we generally want quick breaths like this to introduce tension to make the following silence more exciting.)

Here’s the final version of our simple chord progression for Mary Had a Little Lamb. Listen for the subtle injection of a G7 chord on “lamb” in the fourth measure:

Our final harmonization of “Mary Had a Little Lamb” — with a G7 to add tension going into the second phrase.

Choosing chord spellings

We’ve achieved a chord progression that is intuitive, obeying the Circle of Fifths, and appropriate, using most of the original chords from the song, but how do we make it singable?

Recall that in barbershop, we have four voice parts that sing chords in a way that maximizes shared harmonics. The lowest voice, the Bass, typically sings the foundational notes of a chord — either the root or fifth. The melody in barbershop is sung by the second highest voice, dubbed the Lead. The Baritone is often below the Lead, singing fifths and fourths with the Bass to reinforce the architecture of the chord, but the Baritone may occasionally rise above the Lead when the melody delves into a lower range. Finally, the Tenor floats on top, spit-shining the sound with sparkling thirds.

Let’s continue!

First, we’ll notate the melody in the Lead part. The melody is the most important facet of the arrangement, so we should design our chord spellings around it. (This particular melody is a bit high in C Major, but we’ll ignore that for this exercise.)

The presumed Lead part of our arrangement, notated first due to its importance.

Next, we’ll add a Bass part. The bass provides the foundation of each chord, sticking to roots and fifths to avoid any semblance of instability at the bottom of our chord stack:

The presumed Lead and Bass parts of our arrangement.

For this melody, we’re able to keep the Bass on the root of each chord (i.e., C for C Major chords, G for G7 chords) almost without issue. The only problem is on “lamb” in the fourth measure, where we now have two parts singing G on what should be a chord with four distinct pitches: G, B, D, and F. In this case, we’ll try knocking the Bass down to the next best option, the fifth of the G7 chord, a D-natural:

Next, let’s add a Tenor part. The primary objective will be to keep the Tenor above the Lead, ideally singing the third in C Major chords if the lead is not already singing it, and taking whichever of the two remaining notes in the G7 chords minimizes large jumps between sequential chords.

The high melody notes in the fourth measure force the Tenor below the Lead on “-tle lamb.”

Again, the fourth measure presents challenges that we must depart from our ideal scheme to overcome. In this case, the Lead is quite high on “-tle lamb”, and keeping the Tenor above the Lead would send the Tenor into the stratosphere without any strong artistic reason to do so. Instead, we concede to have the Tenor drop below the Lead line for two notes before returning to the top spot again on “Ma-” in second system. Even simple songs can require us to break with convention!

Finally, we fill in the leftover notes in the Baritone part. The focus for the Baritone on I chords will be to sing reinforcing fifths if no other part is already singing a fifth, or an octavized root if so. On G7 chords, the baritone will simply sing whichever note remains — hopefully without requiring too much of a jump between chords.

The full barbershop harmonization, complete with the Baritone part.

Since the Baritone part is typically constructed last using the leftovers, it is often the least intuitive to sing. There may be frustrated leading tones and other curveballs that will force Baritone singers to remain on their toes. Experienced Baritone singers expect this to be the case and may even enjoy the challenge, but arrangers should still strive to treat every voice part as graciously and avoid unintuitive motions whenever possible.

Here is an audio sample of the final arrangement:

Even with just two chords at our disposal, there is much to keep in mind as we arrange for barbershop. The Lead should receive as much of the melody as possible to allow for maximally expressive singing. The Bass should receive roots and fifths to lay a strong foundation on which the harmonics from all four parts can stack. The Tenor should remain above the Lead as much as is reasonable, but know when to sneak beneath in key moments. And the Baritone should navigate the thorny remains, swinging masterfully between contrasting roles as a powerful supplement to the Bass and a delicate complement to the Lead. And underling it all is the chord progression, the most important facet of our arrangement’s architecture, that typically abides by the Circle of Fifths.

Of course, using only two chords will get boring quickly. How do we enrich our harmonic toolkit?

Take 2: Trying other Circle-of-Fifths paths

Let’s introduce a few more chords to our vocabulary. A greater range of chord options will allow us to harmonize Mary Had a Little Lamb differently, making successive verses potentially more varied and interesting. Here’s the new diagram describing our allowed harmonic progressions:

A diagram describing an expanded set of chord-progression rules for use to use. (Generated at http://madebyevan.com/fsm/)

Note that we now have a new permitted end state, vi (A minor), and two new seventh chords, III7 and II7. Our two new seventh chords still progress according to the Circle of Fifths; however, each requires a pitch outside of our C Major scale:

Our two new dominant 7ths chords, each of which includes a pitch outside of the C Major scale.

In classical music theory, you’ll hear such chords labeled “secondary” dominant chords, because they “borrow” pitches from other keys (D7 borrows an F#, and E7 borrows a G#).

Variant 1: The Barbershop-standard II7-V7-I

The addition of D7 allows us to create an even longer resolution path along the Circle of Fifths using a II7 → V7 → I progression, strengthening the barbershop character of our arrangement. It sounds like this:

Generally, barbershop arrangers should strive to include this progression in every arrangement to maintain stylistic credibility. It is so convincing that it can almost stand alone as both necessary and sufficient to call an arrangement “barbershop.”

Here’s what the first two measures of Mary Had a Little Lamb might look like with the D7 chord in the mix. We follow the same chord-spelling process as before in order to choose which pitches go in each voice part:

The first two measures of “Mary Had a Little Lamb,” re-harmonized with a II7 → V7 → I progression.

This harmonization is a less true to the song’s original chords and thus feels a bit out of place in this instance, but it fits the melody notes and is certainly an option for us to consider as we forge ahead in a longer arrangement.

Variant 2: Ending in minor

A more dramatic change of tone would be to end in A minor (vi), which our diagram now permits, approaching via a III7 → vi progression:

A dramatic re-harmonization of “Mary Had a Little Lamb,” ending the first phrase in A minor.

The minor cadence casts a grim shadow over what was previously a quite saccharine phrase. This is a bold choice that is actually fairly common as a tool for adding variety in later verses, but it should really be used only when it makes sense with the lyric.

Take 3: Allowing any Circle of Fifths path

We’ve now seen how we can incorporate the canonical II7 → V7 → I progression and the III7 → vi progression into our simple melody. To close, let’s try one more version that demonstrates how we might incorporate as much of the Circle of Fifths as this melody will allow: a four-step resolution from III7 → VI7 → II7 → V7 → I.

This won’t be possible to fit into our melody if we assign one chord to each melody note, but we can achieve it if we slow down our melody and use two or three chords before moving on. This is something arrangers might do in a refrain toward the end of a song—especially in the tag, a barbershop arrangement’s coda or outro, in which the primary melodic motif is repeated with a particularly poignant harmonic treatment.

Here’s our new chord progression diagram:

Our new chord-progression diagram, which now allows us to jump back four hops on the Circle of Fifths. (Generated at http://madebyevan.com/fsm/)

And here are the pitches contained in the above chords relative to C Major (again, pardon the wonky inversions of these chords in this graphic; the inversions are just necessary to show all of these chords within one octave):

The pitches contained in the III7, VI7, II7, and V7 chords relative to C Major.

Our goal will be to move from left to right and loop back to the start again—that is, from C → E7 → A7 → D7 → G7 → C—while also ensuring that the current melody note always fits into each successive chord. To accomplish this, we’ll need to move our melody more slowly relative to the harmony parts.

Using the same techniques as before—keeping the Bass on roots and fifths, the Tenor slightly above the Lead, and so forth—the arrangement below shows one way to slow down the melody to make the chords fit:

“Mary Had a Little Lamb,” reimagined as a slow, plaintive tag in order to fit a four-chord Circle of Fifths resolution.

Here’s how it sounds:

Note that the Bass starts in unison with the Baritone on the high C in this case. This is a perfectly appropriate tactic to employ on occasion: we’re still left with the same three-part chord, but we now minimize jumps for the Bass between the next few chords while still letting the Bass remain on roots or fifths at all times.

This definitely dresses up the melody in a new and interesting way appropriate for a tag, but there are a couple issues. For one, the harmony parts are a bit uninteresting when they repeat the same chord multiple times, as on “-ry had” and “lit-tle lamb.” Second, the rhythm sounds a bit stilted: it would be lovely to tweak it to suggest how a quartet might interpret this passage with a bit more freedom.

Here’s a new version that aims to address both of these points, while using only the Dominant 7 chords permitted by our current progression diagram:

“Mary Had a Little Lamb” as a slow, plaintive tag again — this time with more interesting rhythmic treatment and a lovely spread on the final chord.

Here’s how it sounds at a slow tempo befitting the mood of the passage:

Note that we’ve accelerated the rate of harmonic motion in the first measure before relaxing into the D7 chord. Then we introduce an emotional rest, followed by a re-spelling of the D7 chord in a different inversion that allows the Bass and Baritone to do something interesting while the progression otherwise stagnates. Finally, we end the passage with a rhythmic punch on “lit-tle” — which perhaps gives the quartet an opportunity to sing that word with a playful grin — before ending on a beautiful, open 1–5–3–1 chord that all harmony singers and the audience now get to look forward to.

Harmonic rhythm

The fact that we made the passage slower—first with respect to the melody’s pacing, then with respect to the actual tempo—is a great example of harmonic rhythm at work. “Harmonic” rhythm refers to the frequency with which the harmony changes over time.

Earlier in this article, in Take 1, we had a fast tempo that changed chords approximately every measure. Measure 1 was predominantly harmonized with C, measure 2 with G7, measure 3 with C, and so forth. In this latest example, we changed chords almost every beat in the first measure—about four times faster than in Take 1.

Generally speaking, the ear needs to dwell on a new chord for a short while before the tension establishes itself strongly enough to make the next progression feel intuitive. When a song is fast, a “short while” might correspond to a measure or two, which we might call a “slow” harmonic rhythm. This gives us time in the fast tempo to establish each chord in the listener’s ear. But we should be careful not to change chords too slowly, otherwise the audience may get bored!

When we slow the tempo, a “short while” may be just a single beat, which we might call a “faster” harmonic rhythm than before, since the chords are changing quickly relative to the melody notes. The slower tempo permits us to be much more creative with our harmonies on each successive melody note, without having the audience fall off the bus along the way.

Here’s a graphic that explains the tricky balancing act with harmonic rhythm:

A simple plot of the relationship between harmonic rhythm and tempo.

Reflection

Hopefully this post clarifies how barbershop arrangers approach their craft at a fundamental level.

Next, we’ll broaden our harmonic toolkit to allow additional types of chords and progressions, and we’ll look at increasingly complex melodies. As we do so, the realm of options available to us will rapidly increase, and we may start to experience some choice paralysis. However, if we rely on the building blocks developed in these first two chapters, we’ll have a solid foundation from which we can confidently explore exciting new musical territory.

Next: Part 4: Same Circle, More Chords
Full guide: Barbershop Arranging: A Modern Guide