Music Theory: Arranging Two-Part Chord Progressions

One of the challenges I've come across in my writing process and the writing process of my production students is creating a two-part chord progression arrangement. It's often easy to come up with a series of two, three or four chords for a loop and create an effective groove for part A. But, when it comes time to transition into the next part, whether it is a 'chorus' of a pop song or 'part B' of an instrumental arrangement, it's not always so intuitive where to take the song. For one thing, there are a myriad of choices and that can be intimidating!

When I talk about 'Part A' and 'Part B' in this article, you can think of those parts as a 'Verse' and 'Chorus' in a standard pop song for example. There are many genres of music and styles of arranging. For the purposes of this article, I am going to explore creative ways to evolve your song harmonically from one part to the next and utilize chord progressions effectively to create more dynamic arrangements. Hopefully these examples will help you come up with creative ways to solve harmonic challenges in your arrangements, no matter the type music you create.

The 'Part A' Progression

Let's start with a simple 'Part A' 8-Bar Progression in C Major:  I-IV-I-IV-I-IV-I-V. This translates to C, F, C, F, C, F, C, G. The I IV tonic/subdominant progression is one of the most common. You can find this in the verse of John Lennon's classic song, 'Imagine.' What's great about this progression is simplicity. We have lots of room to evolve from this harmonic base. I throw in a dominant V chord at the end of the progression to help create tension for our transition to part B. 

Here's the Part A Chord progression played over a simple beat: 

Part A Chord Progression I-IV-I-IV-I-IV-I-V

As we move forward from here, keep in mind that a strong melody often dictates the chord progression and its rhythmic movement. This is something I can cover in another article. The examples in this article will be helpful from the standpoint of not necessarily having a melody and working on the chord progression only. It's also important to note that I use chord inversions and voice leading between chords, not just root progression chords.

Let's Look at Some Options...

Stay away from I chord in Part B

If we stay in the key of C Major without 'borrowing' a chord from another key, there are 7 basic chords to choose from when building a basic chord progression:

I C Major

ii D Minor

iii E Minor

IV F Major

V G Major

vi A Minor

vii B Diminished

The Part A progression relies heavily on the Tonic or I chord so one option for Part B would be to avoid the I chord entirely and experiment with the others. Here's one example using four chords to create Part B: ii-V-ii-IV-ii-vi-ii-V. This progression relies heavily on the subdominant ii chord alternating between IV, vi and the dominant V Chords. Since I avoid the I chord, there is a lifting or traveling feeling to Part B. Think of this as traveling from our home base and not coming to rest until Part A begins again. To make things more interesting, I change up the rhythm a bit and hold the ii chord in the beginning of the progression instead of change each chord at the beginning of the measure. Also, I create quick changes between chords. 

Listen to an example of Part A into this Part B progression and then back to Part A:

Here's another option with the I chord substituted for the IV and vi chords in the previous example. You will hear a distinct difference in the 'feeling' of the progression between using the IV and vi in the first example and the I chord in the second. 

Part B - ii-V-ii-I-ii-I-ii-V

Get Deceptive with the vi chord

Usually, you'll find a dominant chord (V or vii) or even a tonic chord (I) at the end of a section or cadence. In a 'deceptive' cadence, the section ends on a vi chord, creating a feeling of longing or suspension. This cadence is used a lot in classical music and modern film music but can also be used effectively in songwriting. The 4-chord progression you will hear below is played two times over 8 bars.

Part B IV-I-V-vi-IV-I-V-vi

iii as alternate tonic chord

The iii chord is considered an alternate tonic chord in a harmonized scale and is an interesting chord to try instead of the I chord. But, since it's minor and used in conjunction with the vi chord in the progression below, Part B gets a more reflective feel before ending on the dominant to bring the song back to the happy feeling of Part A.

Part B vi-iii-IV-iii-vi-iii-IV-V

Time to Borrow

If you're bored with the 7 basic chord options available in the key you're in, start playing around with substituting chords from other tonalities that sound good. Often, I stumble upon chord progressions accidently while jamming. When I hit something I like, I figure out what key I'm centered in and what key the 'borrowed' chords are likely from to complete my harmonic and melodic picture. In the example below, I used a Major III chord, which is the dominant or V chord in A minor. A minor is the relative minor of C Major so that substitution works well. In the second half of Part B, I re-establish the home key and cadence before going back to Part A.

Part B Borrowed Chord  vi-III-vi-III-IV-I-IV-V

Find Your Chords!

Coming up with harmonic arrangements takes time and practice. My suggestion is allow yourself to experiment at the keyboard, either in a key or freely, to find chord progressions you resonate with. You'll also find inspiration by studying scores or lead sheets from favorite artists. There's no shame in mimicking other artists ideas' and then finding your own variations. This is a great way to develop your ear. As you experiment, you may hear the perfect melody while playing the chords and then you know you'll have something special.