The ii-V7-I progression and V7 to ii7 chord substitution

This lesson covers a very important topic and is quite lengthy.  If you find yourself in deep waters, you might revisit previous lessons about how to identify and name chords (look in the “Theory” section here).

In modern music, the most popular chord progression is the ii-V7-I.  Believe it or not, you can build entire songs just by repeating this progression over and over, and many of those songs exist.

If you want to see a ii-V7-I progression, look at the ending of almost any modern song of any genre.  In previous centuries, composers used a V-I cadence and later discovered the V7-I cadence.  Then the minor ii chord began to be used before the V7, and has been used ever since.

Take a moment and play the three cadences on the piano.  You will note that the V-I has an air of finality about it but still seems missing something.  The V7 is a much more satisfying cadence because the added 7th creates a tritone with the 3rd that wants to resolve to the I chord.  However, the ii-V7-I cadence easily sounds the best of the three.  If you are looking for a way that music harmony has improved over history, here is an obvious example.

Note that the ii chord is a fifth above the V7 which is a fifth above the I.  This is very important–I have told you before that when in doubt, play progressions around the circle of fifths.  In fact, one very effective chord progression I use is IV-vii-iii-vi-ii-V-I.  All of those chords usually have sevenths added, and the vii is actually half diminished, but the point is that the progression is built entirely on the circle of fifths.

I have told you before that I am going to cover chord substitutions from the prospective of functional harmony, meaning how chords relate to the chords around them. So far we have talked about the ii7-V7 progression, but here is an important related concept–the ii7 chord can always be substituted for a V7.

For your information, modern musicians do not even call this a substitution.  It is just an assumption.  Those that are familiar with functional harmony will go so far as to say that the ii7 and V7 are the same chord!  The first time I heard this, I was hopelessly confused.  After a time, I realized that they mean that the two chords have the same  function.  I will talk about this more later, but essentially they mean that the two chords want to resolve to the same place.

Remember that we extend most major chords by adding a 7th and possibly 9ths, 11ths, or 13ths?  With that in mind, here is a V7 chord in the key of C with all its possible extended notes.  Right beside it is a ii7.

Note that the ii7 (D minor 7) chord is a subset of the V7.  Modern musicians have learned about these kinds of relationships and as a result, play a lot of minor 7th chords.  One prominent musician (I can’t remember who) claimed to have invented a way to play on “top” of the chords.  This is what he was talking about–you can see that you could say a ii7 is the top of a V7.

Substituting minor 7th chords for major chords will make your music sound more mellow.  Minor 7ths are largely responsible for the way my personal style sounds.

With all that background behind us, let’s get practical.  I asked you last week to analyze the hymn “Trust and Obey”, label the chords and identify V chords.  Then, you were supposed to try to substitute ii7 chords for the V chords.

First, here is the hymn the way it traditionally might be harmonized in a hymnal.  I have already labeled the chords.  If you cannot understand how I named the chords, please revisit the lessons mentioned at the top of this lesson before you proceed.

When reharmonizing this song, we are going to focus on the following objectives:

  1. Substituting the ii7 for the V7.
  2. Substituting ii7-V7-I cadences for V7-I.  (By the way, note that one already exists in the third line.)

Before I show you a reharmonization of this song, I will tell you that I changed many other things as well.  For example, I have added many 7ths that really give it color.  Remember that adding 7ths is easy–you normally add minor 7ths to every chord but the I and IV chords (those normally work best with major 7ths).

I have also added some color notes just because I can’t help myself.  Ignore those notes for now if you want.  The root, 3rd, and 7th are the critical notes you need to find to identify every chord in this song.  Also, remember that I rarely use inversions, so assume that the bottom note is the root.  If it is an inversion, I will note it as a slash chord. (Example: F/C is a F major chord in 2nd inversion.)

Now, let’s take a look at what I am doing.  It would be helpful to print off both versions and put them side by side.  Remember that in the key of F, the ii7 is Gmin7 and the V chord is C7.  We are going to focus just on those two chords.

The first V7 in the song is at the end of measure 1, but I chose not to change it.  Doing so would have created a I-ii7-I progression, which is OK, but certainly not an improvement over what is written.  That being said, one option I could have done there would have been to change the chord on the beat right in front of the V7 to a ii7.  That would have created a I-ii7-V7-I progression which sounds great.

Measure 3 is the first place I substitute the ii7 for the V7.  However, notice I change the chord only for the first two beats, leaving the V7 in place for the last beat.  That creates the ii7-V7-I progression.  (This is repeated at measure 11.)

In the first version, you play one V7 chord for five beats across measures 7-8.  I changed measure 7 to ii7 and measure 8 to V7.  This creates movement (and a ii7-V7-I progression).

At measure 16 (start of the chorus), I change three beats of V7 to one of ii7 and two of V7. At the risk of sounding redundant, that creates another ii7-V7-I progression.

The minor ii found in measure 19 already existed in the first version.  I did add a 7th to it.

Finally, in the last two measures, I changed a I-V7-I cadence to ii7-V7-I.  This required me to change a I chord to a ii7 chord (first beat of measure 22).  We have not really talked about this substitution yet, but it works well because the measure in front is a I chord.  So, instead of staying on I for five beats, I truncated the I chord to three beats, played ii7 for two beats, and then V7 to I.

This has been a long lesson, and I will continue this topic next week.  As you can see, chord substitutions often involve changing one chord into multiple chords.  Also, note that the progression itself is an important part of the decision to change a chord.  Remember that I chose not to do a substitution in one place solely because it creates a weak progression.

Practice Strategy

Work through this arrangement of “Trust and Obey” and make sure you understand what I did in this lesson.  Then pick another hymn and go through the same exercise. Identify V7 chords and try to substitute ii7 chords where appropriate.