Tension and Resolution
If I had to reduce music down to a single idea, it would be tension and resolution. Everything we enjoy when hearing music is a constant back and forth between states of musical tension and resolution. This happens with every element of music: melodic, harmonic, rhythmic, dynamic (loudness of notes) and timbral (tonal color).
Most often it is a combination of these tense and resolute elements which make music exciting and interesting. For example, a tense, syncopated rhythm combines with a tense harmony leading to a resolved, on-the-beat rhythm combined with a resolved harmony.
To play and create good music, you must learn to control tension and resolution with every element of music.
Harmonic Tension and Resolution
In a chord progression, you can create these states of tension and resolution with as few as two chords.
A very common progression in both major and minor keys bounces between a resolved I chord (or minor key i chord) and a tense V chord. Since this progression is so basic and fulfills our need for tension and resolution, it happens in just about every musical style.
I should warn you to be careful thinking songs which just stick to two chords are too simple or boring. If you have tension and resolution, you have all you need. Things don't have to be complex to be good. And, often, when one element is simple some other element picks up the slack with more complexity. Simple harmony? Complex rhythm. Simple rhythm? Complex harmony.
i-V-i Exercises and Songs
I've made a few exercises going between the i and V chords in a minor key. We've done a bit of this in the earlier lesson on the use of the major V chord in a minor key. These exercises emphasize the diatonic chord positions with the A-string tonic.
I've included a few song examples, too. There are many songs you will hear which just stick to these two chords, and there are even more songs which do this most of the time but also have a few other parts mixed in for added contrast.
This minor i-V-i chord progression should sound familiar to you. Listen to the exercises and song examples and you will really get a sense of the harmonic tension and resolution effect it creates.