As many of you have noticed, I don’t modulate very much. The main reason I don’t modulate much is because I really don’t find it very necessary or helpful a lot of the time. In general, if there is no compelling reason to do something, I won’t.
I should note that when I am talking about modulation in this post, I am not referring to the type of modulation that goes on in the song form itself. I find that kind of modulation awesome and it makes the song musically deep. The Christmas classic “Winter Wonderland” is a great example. It changes keys two times in the bridge and then returns to the main key to get back to the A section.
If you exclude that kind of modulation, the only real reason I can come up with for modulating is to sort of lift the energy of the song to a higher plane. This is obviously done all the time and it can become a big cliche. I hate cliche and so I use it sparingly.
The arrangement of “Does Jesus Care?” last month is one of those cases where I went for a modulation. I wanted it to build pretty big in a hurry and a modulation just felt right. Today, I want to talk about the modulation I used. It is not complicated and the formula can be used over and over if you want to go up a whole step.
This particular modulation is a pivot modulation which means that a chord that exists in both keys is used as a bridge between the keys. Here it is:
One thing I want to mention before I go on is that I am using slash chord notation here, which means the slashes you see between chords indicates an inversion of sorts. (This can be confusing because you often see slashes used in a different way.) However, here, when you see V/IV above, I mean that you are playing the V chord (C) over the 4th degree of the scale (Bb) in the bass. V/iii means C/A or a C chord played over an A in the bass. (You could also call V/iii just iiim7 and you would be right.)
The pivot chord occurs in bar 41. V/iii (iiim7) is also the ii chord in the target key (G) and we are going to use it to bridge between the keys. That is why I have notated ii in parenthesis.
If you treat that Am7 pivot chord as the ii chord in the new key, you know that you just have to move to V and your modulation is done. If you play a ii-V in front of a target, you pretty much establish a tonal center. So, Am7 – Dsus7 nicely gets you to the new tonic (G) in bar 43.
Now that we have looked at where we go once we hit the pivot chord, we can take a brief look at how we arrived at the pivot chord in the first place. Here is what I did: I used what is called a descending cliche where I walked down the bass notes. This is called a cliche for a reason because it is also widely used. Descending cliches are formulaic only in that they are descending bass lines by step. The actual chords and inversions used to step are negotiable and for that matter, the steps can be either whole steps or half steps.
In this case, my descending cliche is short and uses a V chord along with a few simple inversions of the V chord to create a 3-chord sequence. The sequence of sticking with a dominant chord and inversions creates anticipation and lends itself to building dynamically. That in turn supports what I am trying to do with the modulation.
That is about it really. I certainly did not come up with this idea and there are many different slight variations of it in a lot of music. I just thought it might be interesting to explain what is happening from the perspective of functional harmony.