Subdominant Chord
We have discussed how the dominant chord resolves to the tonic. Now we'll talk about one more very common chord: the subdominant chord, built on the fourth position (scale degree). For the C major key, the subdominant is F major, and the dominant is G major. Together, these three chords cover a lot of melodies!
The subdominant chord opens the melody for some development, going away from the tonic. It is often followed by the dominant chord, or the melody can go back to tonic.
Try pressing C, then F, then G, then C again. This is a very common chord sequence!
An alternative, and also common, is to go back to the tonic from the subdominant. Try pressing C, F, C, G using the buttons above, to hear how that sounds.
Examples of the subdominant chord usage
Now, with the subdominant, we can fully complete the chord sequence for “Happy Birthday”. Let's take a look at the second phrase. Note what happens when we sing “Happy Birthday to <Name>”: it's the subdominant! Try playing F major there, I marked that place with green:
Let's do one more simple example, also in C major, so the subdominant is F major and the dominant is G major.
In the minor keys, the subdominant is also a minor chord. For example, for A minor, the subdominant is D minor, and the dominant is E major: remember, the dominant is always a major chord. Try playing the very popular chord sequence Am Dm E Am to hear it:
Subdominant chord in the minor key
For the next example, we'll go as far as to the famous Mozart's Symphony No. 40 in G minor!
In G minor, the subdominant chord would be C minor (built on the 4th note), and the dominant chord will be D major.
Of course, there are no actual chords in the score, but it's still very easy to hear the motion between the minor tonic (G minor), its subdominant (C minor), and the dominant (D major) in the first few measures.
Practice
Now I'll let you practice! We'll use “When the Saints Go Marching In” as an example. First, listen to the melody and try to guess what key it is in. Two questions:
- is it major or minor?
- what's its tonic?
I hope you guessed correctly: this melody is in F major.
Now, if the tonic is F major, what would the subdominant and the dominant chords be?
Take your time to calculate the fourth and the fifth notes for F major: the subdominant chord is B♭ major, and the dominant is C major.
If you were unsure about the flat, don't worry! When you get used to it, you will just hear the correct interval between the tonic and the subdominant. But for now, you can memorize it this way: the dominant is always built on the highest note of the tonic triad–that is, for F major, the triad is F A C, so the dominant chord is built on C and is C E G. The subdominant is always one full step–two piano keys–below the dominant, so, for F major, it will be B♭ major (the black key), not B.
With that knowledge, try listening to the melody and figuring out where to play the tonic, the subdominant, and the dominant! I'll give you the buttons this time:
Finally, this is one of the acceptable harmonizations! There is no single correct answer here, especially given that this melody is often played by jazz bands; but the following chords will work:
Congratulations, you know the three main chords used in harmonization: the tonic, the subdominant, and the dominant! It's surely not the complete list of what you would need, but it's a strong start.