The Trick to Writing a Functional Chord Progression
The year was 2013 and I had just entered my first music theory class. I knew the common chords like major and minor but I had no clue how to use them to create great sounding chord progressions. Up until that point I had only gone through basic high school music theory and had no clue of what the word diatonic even meant. Then my mind was blown by the concept of functional harmony.
I was quickly introduced to the fact that every scale had chords that were derived from each scale degree, something that isn’t that mind blowing to think of now but at the time it was as if a major lightbulb had gone off. Better yet, the class introduced me to the idea that each of these diatonic chords had certain functions which classified how they wanted to resolve. After that I was hooked and went away and experimented with absolutely every combination I could think of. Not only did I now have a set of chords that I could draw from when I wrote music, I also had a system which dictated how I could prolong or shorten resolutions.
A couple of months later and functional harmony started to serve as a fantastic analytical tool to understand the chord progressions of some of my favorite artists. However, I did get a bit ahead of myself at the time and didn’t know all of the tricks mentioned below, which led to some very interesting (and incorrect) analysis results. Although I had fallen in love with functional harmony I actually hadn’t been taught why it worked and it wasn’t until years later when I started teaching it myself that I realized the true mechanics of the system. Realizing that the core component of the functional harmony could be boiled down to the movement of two specific notes.
Before we jump into the nitty gritty, functional harmony provides a perfect stepping stone from where the previous section on intervals leaves off as it helps unpack how diatonic chords feel within the context of a key. Instead of thinking about chords and intervals in a vacuum, it gives us a set of rules which will help provide a foundation to writing chord progressions. This is only one approach to writing music and if you have found chord progressions you prefer that don't fit under the scope of functional harmony, there is nothing wrong with that. You should write the music that you like, regardless of whether it can be justified by theory.
The Tale of Two Notes
The key to understanding how diatonic chords function is by first knowing where harmonic tension and resolution occur within a key center. Typically, harmonic tension is created by moving away from stable chord tones (the first and third degree of a scale) with resolution taking place when you return to those same chord tones. An example of this can be seen in the key of C major, where the stable “home” chord tones are C and E. If you were to move away to adjacent diatonic notes, you would create a harmonic pull that would want to return to the original C major chord.
Additionally, within a major key there are two notes which create a higher level of tension due to being a semitone/half-step away from the stable chord tones. These notes are located on the fourth and seventh degree of a scale (in C major that would be F and B) and want to resolve to the third and eighth (first) respectively. Any chord which makes use of one, or both, of these notes will have a level of instability.
When these notes are combined together into diatonic chords, the instability is mapped out through the labels Tonic, Pre-Dominant, and Dominant which help us understand where each chord may want to resolve. These are different to the common naming system which uses words like Tonic and Mediant to describe scale degrees.
Tonic (T) - chords which are stable and are fully resolved
Pre-Dominant (PD) - chords which are partially stable and want to resolve
Dominant (D) - chords which are unstable and want to resolve
Diatonic Chords
The process to find diatonic chords is simple, first you map out the seven notes of a major or minor scale and then you create triads above each one. When stacking thirds to create the triads, be mindful of the key signature as it will affect the quality of specific chords. Fortunately, scales of the same type, such as major, all share the same diatonic chord qualities regardless of key. So one handy piece of advice is to memorize the qualities, that way if you misplace an accidental it will be easier to spot.
Now that we know what chords exist within a key center, we can look at adding functions to each one.
I - Tonic, features the first and third degree of the scale.
ii - Pre-Dominant, features chord tones adjacent to the first and third degrees of the scale. The inclusion of the fourth degree adds some level of instability to the chord.
iii - Tonic, the III chord is a special case as it doesn’t quite feel resolved but doesn’t quite fall into any of the other categories. Many musicians avoid using it for this reason
IV - Pre-Dominant, features chord tones adjacent to the third and fifth degrees of the scale. Although it also includes the first degree, the inclusion of the fourth degree adds instability where the chord doesn’t feel fully resolved.
V - Dominant, features the seventh degree of the scale which is the most tense tone.
vi - Tonic, features the first and third degree of the scale.
vii° - Dominant, features both the seventh and fourth degrees of the scale which create a high level of tension
The Chord Resolution Formula
With the chord functions under our belt, the fun can begin. A large majority of Western music is built around the concept of chord function whether it was the composer's intention or not. Beginning sometime in the Baroque era (or perhaps late Renaissance), musicians began to write music that followed a sense of resolution. Something that would start resolved, go away to some level of instability, and then come back again. It is from this concept that functional harmony was derived and it can help us today to write great chord progressions.
By understanding that Tonic chords (T) feel stable and resolved, Dominant chords (D) are unstable, and Pre-Dominant chords (PD) are somewhere in between, we can map out a basic chord progression formula which goes T - PD - D - T. So let’s see if it works. Below is an example of a four chord progression in C Major which goes vi (T) - ii (PD) - V (D) - I (T). Can you hear how it starts stable, moves away, becomes unstable, and then finally resolves?
Okay, let’s try another example using different chords. This time it will be I (T) - IV (PD) - vii° (D) - vi (T).
Now both of these examples are just little excerpts I’ve created from scratch to demonstrate the technique, so let's shift gears and look at some real music. Up first we have one of the most well known classical composers, Mozart (I promise we will get to more relevant artists soon). Although many of his compositions follow functional harmony, one of his most famous compositions Eine Kleine Nachtmusik is a fantastic example of the functional formula.
In the first four bars it clearly shows the chord progression G (T) - Am/C (PD) - D (D) in G Major. There are many ways of analyzing this example so there’s no issue if your interpretation differs from mine. The main takeaway is that when you listen to it you can hear the path of resolution. It starts at homebase, moves away slightly, becomes more unstable, and then in bar 5 it resolves back to a tonic chord.
Eine Kleine Nachtmusik
Amadeus Mozart
Although Mozart is definitely a classical composer, this same idea can be found in all different sorts of music. For example Taylor Swift’s Shake It Off also uses functional harmony.
Shake It Off
Taylor Swift
Interestingly, Shake It Off doesn’t use any Dominant function chords and instead opts for a repetitive progression of Pre-Dominants and Tonics. What this demonstrates is that just because there is a certain resolution formula that exists, you don’t have to keep to it when you write. And I’m going to go out on a limb here but I suspect Taylor Swift wasn’t thinking about functional harmony when she wrote that chord progression.
Shake It Off also makes use of a different cadence than the examples beforehand, opting for a IV-I between C and G. A cadence is simply the main resolution point in a progression. There are four primary types (with many subcategories for those who really love music theory) which cover the variations which exist in diatonic harmony. In the case of Shake It Off we have a plagal cadence.
Typically referred to as the “Amen” cadence, the plagal cadence is when you resolve the IV chord to a I chord. This style of cadence is most commonly used in hymns and Christian related music, both from centuries ago and recent years, as well as in Gospel and Blues styles. It gets the “Amen” nickname due to the consistent use over the word amen at the end of Christian hymns. But as you can see it is also very popular in Western pop music. These days, most songs in the Billboard Top 40 feature some kind of plagal cadence.
For those that are interested, there are three other primary types of cadences: Authentic (V-I), Half (V), and Deceptive (V-vi). Each of which we can see in the prior examples to some degree. Authentic cadences are by far the most popular in jazz and give the strongest sense of resolution due to shifting from a dominant function chord to a tonic. The half cadence concludes unresolved, with the music lingering on a dominant function chord. Finally, the deceptive cadence gets its name from resolving to a somewhat unexpected chord, surprising the listener. Commonly this is to the vi tonic chord, but nowadays it can really be thought of as any chord which feels unexpected.
Plagal Cadence
(IV-I)
Authentic Cadence
(V-I)
Deceptive Cadence
(V-vi)
Half Cadence
(V)
Shifting back to chord progressions, Stevie Wonder’s Isn’t She Lovely provides another fantastic example of functional harmony which follows the T - PD - D - T formula.
Isn’t She Lovely
Stevie Wonder
If we look closely at the chords, we see that the second chord is a little bit different to what we might expect. Instead of using the traditional ii chord (F#m) from E Major, Stevie Wonder opts for another PD chord. In this case a secondary dominant.
Secondary dominant chords are diatonic but they operate a little differently. The technique came about during the Baroque period and has been used considerably ever since as a way of introducing chromaticism into a chord progression. As the name suggests, a secondary dominant is a chord with a dominant quality (not a dominant function) that comes from a secondary key center. By thinking about any diatonic chord in a progression as the tonic of a new key center, you can then pull other chords from that secondary key to help elongate a passage and add chromatic tones. The most common option is the V chord as it naturally wants to resolve to the I chord.
If you’re new to this concept, that last paragraph might seem very confusing. I know it didn’t make sense the first time I was introduced to it. So let’s go back to Isn’t She Lovely to understand the technique a bit more practically. In bar 2 we get an F#7 chord but if we look at the chords of E major (the key of the excerpt), F#7 doesn’t exist. So how can we justify that chord through functional harmony? To do so we have to look at bar 3 and work backwards.
The B7 in bar 3 can be analyzed as a secondary key. Alongside being the V chord in E major, it can now also be thought of as the I chord in the key of B major. If we shift focus back to bar 2 and the F#7, by looking at it in the context of B major we can label it as a V chord. Due to the excerpt being thought of in the key of E major, this brief shift for bar 2 is called a secondary key, and thus the V chord is referred to as a secondary dominant chord. When labeling a secondary dominant in analysis, we use the V/ symbol prior to the chord it resolves to. In the case of Isn't She Lovely the F#7 would be labeled V/V as it is the secondary dominant of the B7.
When we look at secondary dominants through a functional perspective, they don’t operate the same as typical dominant chords. Instead of taking a dominant function, they actually take a pre-dominant function. While secondary dominant chords still feel unstable and take on high levels of tension, the path of resolution isn’t the same and they don’t want to resolve to tonic chords. As a result, they are classified as PD in the primary key.
With all of that in mind, taking a look back at the four bar excerpt of Isn’t She Lovely we can see that it does in fact follow the T - PD - D - T formula. And for extra credit, the excerpt also uses an authentic cadence (V-I) between bars 3 and 4.
So we’ve looked at classical, we’ve looked at pop, but we haven’t looked at jazz, which is a bit sad considering these resources are all about jazz arranging. For our final example, let’s have a look at one of the classic jazz standards made famous by Frank Sinatra, Fly Me To The Moon.
Fly Me To The Moon
Bart Howard
Looking at the first 4 bars, we can clearly see the classic T - PD - D - T formula but unlike the previous examples the progression continues to include more chords. This nicely introduces the idea that chord progressions don’t have to be limited to one set of repetitive chords. In many cases repeating three or four chords can work really well, but other times you may want to create more elaborate progressions which cover more harmonic ground. To do so we have to change how we think about the formula.
The idea of T - PD - D - T doesn’t have to be restricted to only four chords. Instead, we can think more broadly and have sections which capture the feeling of each chord function. We can also string together multiple sets of the formula together, mixing and matching different options for each function. By incorporating different cadences, not every part of a progression needs to follow the formula so strictly either. The world is your oyster and there are so many “correct” options in the eyes of functional harmony.
In the case of Fly Me To The Moon, it strings together multiple sets of T - PD - D - T resolutions and adds a few curveballs to keep it interesting. After the standard first 4 bars, bars 5-8 get a little more spicy, especially in bars 7 and 8. The E7b9 in bar 7 is another example of a secondary dominant chord, this time into the secondary key of A minor, and is labeled V/vi. Unlike the Isn’t She Lovely example, because this is a secondary dominant which resolves to a tonic function chord, it is classified as a dominant function (not as a pre-dominant like all other secondary dominants). Then in bar 8 we see the use of another secondary dominant chord in the form of A7 which would be considered V/ii. As a result, the first 8 bars of Fly Me To The Moon strings together a typical T - PD - D - T in the first 4 bars and a variation in bars 5-8 which makes use of secondary dominant chords.
Final Thoughts
So where does that leave us? Well, hopefully by reading this information you now understand functional harmony to a better extent. This page is only meant to be an introduction to the topic and there are so many other facets to still be explored, but those will have to wait for another day. Together we’ve explored what functional harmony is, and a few interesting techniques such as cadences and secondary dominants.
I would encourage you to go away and have a look at some of your favorite artists and try to analyze their progressions. Once you’ve found certain sounds you like then try to apply them in your own writing. If that’s not quite you, then jump straight in and try to come up with some awesome progressions right now. With the techniques explored on this page, there have literally been hundreds of years worth of music created, so it should keep you busy for a little bit.
If you find a sound you like and it doesn’t quite fit the mold of functional harmony, you should still use it. This is only one method to creating chord progressions and there is no wrong way to write music. You should let your ear lead you to the options you like the best. Remember, if it sounds good and feels good, then it must be good!
And if you’re wondering what’s next, well I’m going to explore even more techniques that you can add to your chord progression toolkit. Specifically diving into the world of substitution, some unique chords like neapolitan and augmented 6ths, and also modulation. All techniques which will help you craft even more sophisticated and colorful progressions.