How To Write Memorable
Harmonic Moments
The year was 2018 and I was in a rehearsal for a show celebrating Leonard Bernstein’s 100th birthday. We started playing an arrangement that Rich DeRosa had written of “Tonight” from the legendary West Side Story and within the first few minutes I was transfixed by the harmony. It seemed as if every few bars there was a key change, with the harmony moving in and out of each one beautifully and taking me on a magical musical journey. I’m not sure whether it was Rich or Lenny who was behind that particular chord progression, but I do know that even though it is now many years later, I can vividly remember that experience. So how can we recreate that sort of feeling in our own writing?
Although that particular chart had a great impact on me as a listener, it wasn’t until 2023 when I took the time to understand the mechanics of the arrangement. I actually stumbled upon the solution through another approach completely, but surprisingly it eventually led me right back to that same “Tonight” chart. You see, in 2023 I went and edited all of the music for a youth program I ran called the Not-So-Big Band. The music had originally been written many years earlier and had to be reorchestrated to fit the current batch of students. Part of that modification process meant modulating sections to better fit the range of each featured instrument. As a result, I realized that the arrangements became considerably more interesting and had a much nicer flow. Even though the sections followed the same progressions as before, by being in a new key and having transitionary chords into and out of the sections, the overall harmony felt less bland and repetitive.
Coincidently, later that same year I decided to write a new set of arrangements for the program built on the music of West Side Story. With Rich’s arrangement being one of my favorites of all time, I had to revisit the score and look at what was going on with the harmony. For the bulk of the arrangement there was a key change every 8-12 bars, moving to related keys and sometimes completely left of center options. Sometimes the sections would transition nicely into one another, and sometimes it would be more abrupt. I walked away realizing that the magic came from the harmony not being repetitive. The listener was being taken on a journey that had no expected cadence points and even when the melody repeated itself, the harmony was different. That particular arrangement may be a more extreme example of modulation with most charts only modulating once, if ever. However, by mastering this technique you can make your progressions feel less bland even when sections are directly copied and pasted throughout.
Now that we know that modulation is the key to writing memorable moments, how do we practically do it? Before diving into the technical side of it all, a lot of the terminology I use on this page relates to functional harmony and specific substitution techniques. If you aren’t familiar with the T-PD-D idea or techniques like modal interchange, have a quick read of these two resources first.
Writing In One Key Is Hard Enough
Changing keys is something most musicians are familiar with. However, most arrangers and songwriters seem to only use one key in the bulk of their writing. Why? Because there are so many options at your disposal within one key center. When you take into consideration all of the diatonic chords, parallel chords, extra chords like secondary dominants and neapolitans, and then throw in inversions, you have tens of thousands of possible combinations (if not more!).
With that said, modulation itself is pretty straight forward. All you have to do is pick a new key signature and jump straight into the associated diatonic chords. The tricky part is how you transition from one key to another. There are many ways to go about this but the two most common approaches I’ve come across are through a pivot chord or an abrupt transition. So let’s have a look at how both work.
A pivot chord is a fun name for a chord which is shared between two keys. When such a chord exists, it allows a progression to pivot between each key signature relatively smoothly. For example, if we look at the keys of C major and G major there are a few similar chords. To keep things simple let’s only look at one, in this case Amin. When a progression in C major lands on an Amin chord, instead of continuing in the same key it can pivot to G major with any of the proceeding chords coming from the new key.
To make it a stronger modulation we can take into account chord function. In this case the Amin is considered a T in C major and a PD in G major. As a result, it wont be as smooth compared to a pivot chord which has the same function in each key (typically can only be PDs). To do this however, we need to look at the parallel chords of each key through modal interchange. For instance, when modulating between C major and Eb major, a pivot chord with a shared PD function is Fmin. Fmin lays outside of the usual seven chords of C major, but is accessible through modal interchange and is the iv chord of the parallel harmonic minor scale.
The trick to finding a great pivot chord is by looking at all of the chords that you have at your disposal for both keys. Remember to consider parallel scales, neapolitans, and augmented 6ths. In a similar manner to what was discussed in the previous resource on introducing dissonance, to help smooth the transition in and out of a pivot chord, you may have to add more chords so the dissonant notes aren’t too noticeable.
A great example of pivot chords in action in the real world is the song “Lucy In The Sky With Diamonds” by The Beatles. Within the first minute there are a number of key changes, all executed through pivot chords. In bar 9 the Dm chord is heard as the borrowed iv from the parallel A minor scale. Multiple times up until this point it operated in this manner so The Beatles have set up the expectation that it will continue in the same way. However, a few bars later a Bb IV chord is introduced, meaning that the Dm two bars earlier was actually operating as a pivot chord into the key of F major. Only a few bars later the band changes key again and uses the C (V chord in F major) as a pivot into G major.
Lucy In The Sky With Diamonds
The Beatles
Other than pivot chords, modulations can happen rather abruptly because there is no reason why you can’t simply shift keys whenever you want to. As a result, the listener gets immediately dropped into a new key and may hear the first few chords in relation to the old home key. It is a wonderful effect if done well and can be very powerful.
Commonly, an abrupt key change takes place between sections when an arrangement needs to step into a new gear. Key changes bring with them a sense of wonder and movement, so anytime a song might feel stale is usually a great place for an abrupt modulation to take place. Pop music does this often, for example Beyonce’s classic “Love On Top” changes key four times, each moving up a semitone/halfstep to create more excitement.
Love On Top
Beyonce
Abrupt changes can also go to keys that are further away than a semitone/halfstep. One of my favorites is in Sting’s “Sister Moon”, which jumps from F#m to Bbm.
Sister Moon
Sting
If you are looking for somewhat of a middle ground between a pivot chord and an abrupt modulation you can use some kind of cadence. Any of the cadences will do, so long as it feels as if we are resolving into the new key. A great example of this is to use the authentic cadence (V-I) by setting up some sort of V chord in the new key directly before the key change. For instance, if you were moving between C major and Ab major, you could put an Eb7 as the chord directly before the progression went to Ab major to help ease the abrupt nature of the modulation.
Getting Lost In Secondary Keys
Modulation can also be done more subtly, interwoven within a single key and not heard as a departure from the home key but more as a brief journey to somewhere related. To do this we have to look back at secondary dominants and expand upon that idea. Instead of having just one chord coming from a secondary key, we can utilize multiple chords for a brief moment. If you are new to this concept, you’d be surprised to find out just how common this technique is, particularly in tunes from the Great American Songbook.
For instance, let’s take the V/ii in C major. For however long you want, you can use not only the A7 but any other diatonic chord in the secondary key of D minor. However, the longer you stay in the secondary key, the more it feels like a modulation and not a brief shift in key.
You can also take this idea and go further by stacking secondary keys. To do this all you need to do is create a chord from a secondary key while already in another secondary key. Now that’s confusing to read but in reality it’s a lot simpler to understand. In the key of C major a V/V would give the secondary key of G major. While in that secondary key you can then do another secondary dominant, also known as a V/V/V which would give you a third key of D major. There’s no limit to how many of these secondary keys you stack on top of each other, just know that the further you go the more it will feel like a modulation.
This particular technique of stacking secondary keys and the related chords happens all of the time in jazz and was a core component of bebop. In Charlie Parker’s famous reharmonization on the classic 12 bar blues, something commonly known as Bird Changes, he goes around multiple secondary keys in the first four bars.
Blues For Alice
Charlie Parker
One of the amazing qualities of using secondary keys is that it changes the perception of the notes from the home key. For example, in C major, C feels like home and is resolved, but in Db major it wants to move upward by a semitone as it is the 7th degree of the scale. When you use a secondary key, or multiple of them, you can play with the audience’s perception of the original diatonic notes, bringing new emotion and feeling to each of them. It is a great device for reharmonization alongside lyrics, and offers a lot of new ways to perceive a single note.
Which Key To Pick
With so many options at our disposal it can often be difficult to know which key to modulate to. Sometimes the options are a bit more obvious due to the restrictions of the instruments we are writing for and other times we have complete freedom. If we wanted to, we could experiment with every single option, a process which would be extremely creative but sometimes one that is not possible due to time constraints. Fortunately, there is a process for identifying how certain key changes will make you feel in relation to the home key. The concept has been around for sometime but in recent years Jacob Collier has done a wonderful job bringing more attention to it.
The idea is to think about the key you are modulating to in terms of distance on the circle of 4ths/5ths from the original key. The direction around the circle will indicate whether the new key will sound brighter or darker. Going around by 5ths create brightness (C > G > D etc) and 4ths create darkness (C > F > Bb etc), and how far away the key is amplifies the brightness or darkness. For instance, if our home key was C major and we modulated to F major, we would be moving a 4th away which would mean the new key would add a small level of darkness. However, if we were to modulate from C major to something like Db major, a key that is five steps around the circle of 4ths there would be a much higher amount of darkness added.
Of course, at the end of the day it is all about how you perceive the shift in key. To your ears it may not feel dark moving around by 4ths and that is completely okay. Trust your ears and go to the key you feel is best, this is simply an approach that may help you find a key to modulate to more quickly.
The Takeaway
Harmony is an amazing part of music with so many ways of creating interest. In my experience, one of the most powerful is modulation. The technique itself helps break repetition and can completely change the harmonic landscape of a piece, even if it is through a brief modulation that may only last a single bar. If you are finding yourself hitting a wall and your progressions feel uninspired, I definitely would recommend giving modulation a shot. It took me years to actually start incorporating the method into my own writing, but now that I can compare my writing before and after, I see that my arrangements are that much better due to changing keys more often.
With the core harmony building blocks in hand it is time to explore the world of color, namely jazz harmony. Up next we dive into the world of extensions, alterations, and where they all come from so that you can start adding a level of harmonic complexity to your music.