The Tonic-Dominant Relationship

We're first going to look closely at the dominant function, it's relation to the tonic - a relationship that will be integral to much of your songwriting.

Dominant chords are an important part of music theory in general, not just on guitar. I won't spend time on what the "dominant" label means, as it's not important what you call it, rather you understand its musical function. You'll hear it (and play it yourself) in the examples throughout the next two lessons.

When thinking about and writing your own chord progressions (a sequence of chords), dominant chords can be seen as natural tension chords before returning back to the starting chord of the progression. By "tension" I mean they have a naturally unresolved feel to them, leaving the chord progression feeling "away from home". So, first, think of dominant chords in relation to a journey away from that starting chord.

Let's say we begin a chord progression with a C major chord. We can call that the tonic chord. That is "home". During the progression, we journey away from home using other chords. Some progressions spend very little time away from the tonic. Others go on a longer journey. However, the dominant function can be used, in both long and short journeys, as a natural gateway to return back home/resolve to the tonic chord.

Take a listen below to a tonic major chord followed by its relative dominant chord, before returning back to the tonic.

Click to hear >

In that example, our tonic chord was C major. The dominant chord was G major. However, the relationship between tonic and dominant chords is the same no matter which key you play in. Take a listen to this same tonic-dominant relationship but in incremental keys:

Click to hear >

...and so on and so forth. When the tonic chord changes, the dominant chord moves with it!

For the moment, it's good to train your ear to the sound/feel of that relationship - the tension of the dominant chord before its return home.

To add to that tension, the dominant chord is often played with a flat 7th. Don't worry if you're not sure what that means yet. All will become clear. We'll look more at this particular aspect next time.

Right... time to really understand this tonic-dominant relationship. Once you do, confidence with your songwriting will improve dramatically, you'll see!

Dominant chords and the major scale

It's surprising just how much music theory stems from knowledge of the major scale. Dominant chords are no different.

Let's take a typical "boxed" major scale pattern:

As you may already know, that pattern can be shifted up or down the fretboard, depending on which key you're playing the major scale in. But let's say we're in the key of G, as rooted on the 3rd fret above.

We could build a tonic major chord over that major scale shape by simply using the E shape barre:

So there's our tonic "home" chord - G major. Now, the dominant chord of that same key is rooted on the 5th degree of the same major scale. Identify the 5th (5) note on the tonic scale/chord above. That is where the root note of our dominant chord will sit...

We can then build the dominant major chord from that dominant root note. I've used the A shape barre in the example below, because its lowest root note lies conveniently on the A string...

Incidentally, in this example, because the tonic chord was G major, the dominant chord is D major. Let's listen to that tonic-dominant relationship again, this time between G and D major:

Click to hear >

To really hear the dominant function in its element, we need to add some chords away from the tonic, and use the dominant chord as the final chord before returning home. A common 3 chord progression is I ii V, which is Roman numerals for: 1 (tonic chord) 2 (2nd chord in major scale) and 5 (5th chord).

Click to hear >

However, any chords you might use away from the tonic (as long as you think they're musical) can interact with the dominant chord in this way.

Now, this tonic-dominant root note relationship between the E and A strings on your guitar can also be identified in other positions where chord root notes occur (e.g. for the common barre shapes)...

Remember, all these positions are the relative positions between tonic and dominant, the same as root (1) and 5th (5) intervals from the major scale. The fret positions are not important, as these are movable relationships. Tonic moves, dominant moves with it. Starting with the one we already know...

So as these are root note intervals, we can build chords on each of them - tonic chords and dominant chords on their respective root note positions!

We also know, from the major scale earlier, that the dominant root note is the 5th of the tonic's major scale, the tonic being note 1 of that same scale.

That, in its basic form, is the I V relationship.

But of course, there's more to it than what we've covered here. In the next lesson, we'll delve further into the theory behind dominant chords and how you can make really effective use of them in your songwriting, especially by using what's called the sub-dominant.

I hope this has, at least partially, opened a new door for you as far as guitar theory goes. Perhaps I've bored you to death in the process. If so, more interactive learning will bring you back to life.

See you in the next part.

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