When I was first learning how to compose music, one of the most frustrating things to figure out was how to write an effective chord progression. I could figure one out through trial and error, but I wanted to know why some chords seemed to go together and others didn’t. Eventually, I learned that the secret has to do with something called functional harmony.
Writing a Chord Progression is deceptively simple when using functional harmony, and can be done in just 5 steps!
Start by picking the key you want to write in.
Identify the chords available in that key, and their functions (Tonic, Subdominant, or Dominant)
Start your chord progression with the chord your key is named after (a.k.a the tonic chord).
Pick the cadence you want to end your chord progression with.
Fill in the remaining space using a pattern of “strong-weak” or “T-SD-D” until the pattern is interrupted by your cadence.
Picking a Key to Work With
Your key is essentially whichever major or minor scale you use to write your music. Choosing which specific key to use isn’t too important at this stage, since you can always change it later. For now, we just need to make sure we know which notes belong in each key.
If we look at the C major scale, we can see that it contains the notes C, D, E, F, G, A, and B, before repeating
If we look at the distance between these notes on a keyboard, we see that the order of intervals between each note follows a pattern. We have a whole step from C to D, another whole step from D to E, then a half step from E to F, three more whole steps connecting F, G, A, and B, and finally another half step to bring us back to C. All in all, we have a pattern of W-W-H-W-W-W-H.
This same pattern can be used to find any given major scale! Just pick a note to start on, and follow the pattern from there! For example, If we Start with D natural and follow our pattern of whole and half steps, we get the D major scale!
The same goes for G natural, Bb, or any other note you'd like to start with. You'll always get a major scale!
We can use a similar idea to find the minor keys. Just pick any random note and follow the pattern of W-H-W-W-H-W-W to find something called the “natural minor” scale!
(there are other types of minor scales but we won’t need to worry about them just yet).
For example, if we start on A natural, and follow our new pattern, we find the "A natural minor" scale.
Identifying the Chords in a Key
Once you have your key picked out, the next step is to identify which chords belong to it.
For this, all we need to do is follow the “add, skip rule”. This rule is very simple, it means we start with one note and add it to your chord, skip the next note in the scale, and add the third, then we skip the next note, and add the fifth.
Starting with the first note in the C major scale gives us a C major triad, where the 1st = C, 3rd = E, and 5th = G. This is the chord that the scale is named after!
We know it’s C major because the interval between the first two notes (C and E) is a Major third, or 4 half steps; while the interval between the second two notes (E and G) is a minor third or 3 half steps. This combination of a major third on the bottom and a minor third on top is what makes a major triad a major triad.
If we follow the same “Add-skip” rule for the rest of the scale; we can build the next chord by starting with the 2nd scale degree, skipping the next note, adding the third, skipping the fourth, and adding the 5th. This gives us a D minor triad.
We know it’s a D minor triad because the distance between the first two notes is a Minor 3rd, and the distance between the second two is a Major 3rd. This is the opposite of the Major triad and is what defines a minor triad.
Following this same pattern, we can find the remaining triads in our key! Put together they are C major, D minor, E minor, F major, G major, A minor, and B diminished (a diminished triad is made up of two minor 3rd intervals stacked on top of each other).
The cool thing about this is that since all major scales follow the same pattern of intervals, they also share the same exact pattern of chords!
1. The first chord will always be a major triad
2. The second and third chords will always be a minor triad
3. The third chord will always be a minor triad
4. The fourth and fifth chords will always be major triads
5. The sixth chord will always be a minor triad
6. The seventh chord will always be a diminished triad.
We can describe these chords using Roman Numerals:
I - ii - iii - IV - V - vi - vii°
Because this pattern of chords is found in every single major key, we call them the diatonic chords of the major key or "the chords that will always appear naturally out of any major scale".
For example, if we wanted to find out what triads were in the scale of D major, all we would have to do is name each of these chords, using the notes found in the D major.
If we applythe same exact add-skip process to the natural minor scale, we find out that the pattern of diatonic chords for the natural minor scale goes:
i - ii° - III - iv - v - VI - VII
Applying this to the A natural minor scale, we would get the following chords:
Starting Your Chord Progression
Once you’ve picked the key you want to work with, the next step is to start your chord progression with the chord your key is named after (e.g., starting a chord progression in the key of “C Major” with the C major triad). This is super important since it helps establish your key at the very start of your progression! Starting with any other chord can run the risk of harming the overall sound and flow of your harmony.
Once you’ve figured out your first chord, the next step is to figure out how you want to end the progression. This helps give you a destination for your overall progression to move towards, which will make writing the rest of the progression much easier.
The ending of a chord progression is called a cadence. You can think of it as the punctuation of your musical sentence. There are many different kinds of cadences you can work with, but the strongest one is called an authentic cadence and is the simple combination of the V chord followed by the I chord.
Since most chord progressions are 8 bars long (with 1 measure per bar) this leaves us with 5 empty bars that we need to fill before our chord progression is complete. To do this, we’ll use something called functional harmony!
Assigning Your Chords Their Functions
Functional harmony is the secret behind guaranteeing your chord progressions will work! The whole idea is that every chord in a scale can be sorted into one of the three-chord families:
The Tonic Family
The Subdominant Family
The Dominant Family
The tonic family tends to be full of “strong chords” or chords that feel stable and solid. Both the subdominant and dominant families contain “weak chords” or chords that carry tension and want to resolve! The dominant family in particular is very weak and wants to resolve to the tonic.
In the major keys, the tonic family consists of chords built on the 1st, 3rd, and 6th scale degrees. So In the key of C major, that would be the C major triad, E minor triad, and A minor triad.
The Subdominant family consists of chords built on the 2nd, 4th, and 7th scale degrees In the key of C major, that would be the D minor triad, F Major triad, and B diminished triad
Finally, the dominant family consists of chords built on the 5th scale degree; or in C major that would be the G major triad and B diminished triad.
Notice how the B diminished appears in two categories. Traditionally it’s always been taught as a dominant functioning chord, but since the early 1900s and the rise of Jazz, it started seeing more and more use in traditionally subdominant functions, so today it just depends on who you ask and how it’s used. However, for our purposes, all that really matters is that you remember the diminished triad is considered a "weak chord"
In the minor keys, the tonic family consists of just the chords built on the 1st and 3rd scale degrees, so in the key of A minor, that would be the A minor triad or C major triad.
The subdominant family consists of every other chord in the scale. There are actually no dominant functioning chords in the natural minor scale.
We could get lost down a rabbit hole of music theory explaining reasons why, but for now let’s keep things simple by saying, you need to add an extra chord anytime you’re working with a minor key.
In addition to the diatonic minor 5th, you’ll introduce a major fifth by raising the 3rd of the chord up one-half step, which gives the key its own dominant functioning chord! Having this extra chord in place gives you a dominant functioning chord to work with and helps transform your natural minor scale into a full-blown minor key!
Finishing Your Chord Progression
Now all of this theory is well and good, but how do we actually apply any of this?
The secret to writing a good chord progression is simply to create a pattern with your chords!
The two most common and reliable patterns are the T-SD-D-T pattern and the Strong-weak pattern.
The T-SD-D-T pattern is exactly what it sounds like, you create a chain of chords that follows the pattern “tonic-subdominant-dominant.” Since your first chord is already a tonic functioning chord, you follow it up with any subdominant functioning chord, and then follow that one with any dominant functioning chord. You can repeat this pattern for as long as you’d like before it either ends or gets interrupted by your cadence.
The Strong-Weak pattern is simpler and offers a bit more freedom. Here the idea is that
all the chords from the tonic family are “strong” and all the remaining chords are “weak”. Starting with your first chord, you simply follow a pattern of “Strong chord, weak chord” until it either ends or gets interrupted by your cadence.
As long as you’re following one of these patterns, any combination of chords you can come up with will always result in a strong and effective chord progression!