The normal song you play in church consists almost entirely of I, IV, and V chords. One of the problems with very simple harmony is that does not move as smoothly as it could. Here is a easy way to improve it.
There is a very important rule about harmony--chord progressions sound smoothest when moving down in fifths. By the way, the tradeoff with this kind of movement is that it is predictable--smooth but predictable. I will discuss this dilemma at another time.
So what can you do to take a normal song and make the harmony smoother? The easy answer is to change the harmony so that it moves down by 5ths.
Modern songs are full of V-I progressions which take advantage of this rule. However, you can improve V-I progressions by extending them to include more chords that move down by 5ths. In other words, a ii-V-I is stronger than a V-I because it contains two moves by fifths. A vi-ii-V-I would be stronger still.
When I see a V-I, I instinctively extend it to take advantage of this concept. Typically, I only add the ii, but sometimes add more chords such as the vi and the ii.
Let's say that you see a V-I cadence in 4/4 where one measure is a V and one measure is a I. Try splitting the first measure in half, putting a ii on the first two beats and a V on the second two beats. You will be surprised at the improved sound.
You could also split the first measure into three parts, putting a vi on the first beat, a ii on the second beat, and a V on the last two beats.
I cannot tell you how valuable this concept is to your sound. Try it and you will see what I mean.
