Chord Function
Chord function describes the role a chord plays in a key. There are three primary functions: tonic (home, stability), dominant (tension, urgency), and subdominant (movement, departure). Almost all harmonic motion is organized around these three roles.
The Three Functions
| Function | Degrees | Feeling |
|---|---|---|
| Tonic | I (also iii, vi) | Stability, home, resolution |
| Dominant | V (also vii°) | Tension, urgency, need to resolve |
| Subdominant | IV (also ii) | Movement, departure, transition |
How Functions Drive Music
The tonic is harmonic "home." When you hear a I chord at the end of a phrase, you feel resolution. The dominant creates the strongest tension — the V7 chord contains a tritone that desperately wants to resolve to I. In C major, G7 (G-B-D-F) has a B-F tritone that "wants" to become C-E. This V-to-I resolution is the most fundamental cadence in Western music.
The subdominant provides movement without the dramatic tension of the dominant. It can lead to the dominant (IV-V-I) or resolve directly home (IV-I, called the "amen cadence" because of its use in hymns). The ii chord is a subdominant substitute preferred in jazz because ii-V-I flows more smoothly than IV-V-I.
Common Functional Progressions
I-IV-V-I (departure-tension-home): the most basic complete progression. ii-V-I (departure-tension-home): the fundamental jazz cadence. I-V-vi-IV (home-tension-emotional-departure): the modern pop progression used in hundreds of hit songs.
In ChordColor
Chord function is implicit in the KEY row's Roman numerals. The 16 built-in chord progressions demonstrate these functional movements in action — select any progression to hear how tonic, dominant, and subdominant interact.