Functional harmony is a set of ideas used to create logical chord progressions where each chord has a definable role. The chord's job depends on its relationship to the tonic chord (I). Some Chords will sound stable and resolved, while other chords will sound unresolved and unexpected,
The aim of this tutorial is to give ideas and understanding to constructing chord progressions quicker, easier, and with more confidence, although some music theory knowledge is needed. Please check out our music Theory tutorial to get up to speed, Found Here
What is a tonic chord?
It's very important to understand the relevance of the tonic chord as the chords only do their intended job in relation to the established tonic chord. A tonic chord is the root of the scale, it feels like the start and the final resolution, it's the chord our ears want, and expect, to hear.
For simplicity, I will work with the C major scale
C Major scale (All the white notes)
We use roman numerals to name their relationship with the tonic chord and these relationships can be categorized into resolved (consonance) and unresolved (dissonance).
A mixture of these makes music more exciting and far more interesting. The unexpected dissonance chords will always want to move back to the tonic to relieve the tension.
So firstly, what chords are classed as dissonance, and what is classed as consonance?
(ii) and (vi) - Week Dissonance
(IV) - Strong Dissonance
(vii) - Strongest Dissonance
Some chords have more dissonance than others, the 4th (IV) and the 7th (vii) have the strongest dissonance. The stronger the dissonance the more desire the listener has for the tonic(I) chord, the home.
(I) - Home Base (tonic Chord)
(V) - Harmonizing chord
(iii) - Resolving chord
These chords have a close relationship with the tonic, Much like the dissonant chords, some constant chords sound more resolved than others, these chords are the (I) and the (V) of the scale.
So what can we do with this information?
In music, dissonance and consonance can be used to create tension and resolution. One way to do this is to start with a weaker dissonance and then build tension by using a stronger dissonance before resolving with a consonance chord. While these principles can be bent or broken, following them can help prevent mistakes when improvising or creating chord progressions.
Some common chord progressions
(I) - (iv) - (V) - Resolved, Unresolved, Resolved
You could also look at enhancing the dissonance before resolving, this works well if the first dissonance chord is weaker than the next.
(I) – (vi) – (IV) – (V) - Resolved, Unresolved, Unresolved, Resolved.
(ii) - (IV) - (V)- (I) - Unresolved, Unresolved, Resolved, Resolved.