Harmonic Progression & Function
Updated: 2026-07-04Knowing individual chords is not enough — what makes music is how chords follow one another. This page covers common harmonic progressions and the principle of harmonic function that underlies them.
Key takeaways
- What makes music is how chords follow one another, not the individual chords alone.
- The circle-of-fifths progression moves each chord's root down a fifth: I–IV–vii°–iii–vi–ii–V–I.
- Harmonic rhythm is the rate of chord change — it makes the same progression feel relaxed or urgent.
- Four functions: tonic, tonic prolongation, pre-dominant, and dominant, flowing tonic → pre-dominant → dominant → tonic.
- The three chords I, IV, V represent the three core functions: tonic, pre-dominant, and dominant.
What is the circle-of-fifths progression?
It's a chord chain where each root moves down a fifth (or up a fourth), using only diatonic notes. The circle-of-fifths progression is a staple going back to the Baroque era (Bach, Handel, Vivaldi). In a major key it runs:
I – IV – vii° – iii – vi – ii – V – I
In minor it is usually i – iv – VII – III – VI – ii° – V – i (using the subtonic VII chord). It's called a "circle of fifths" because each chord's root moves down a fifth (or up a fourth) from the previous one — a chain of descending fifths using only diatonic notes. Countless songs are built on it, from "Fly Me to the Moon" to "I Will Survive."
What is harmonic rhythm?
It's the rate at which chords change — how long each chord lasts — and it can make the same progression feel completely different. Harmonic rhythm is the rate at which chords change — how long each chord lasts. The same progression can feel very different depending on harmonic rhythm: changing chords once per measure feels relaxed, while changing every beat feels urgent.
What is harmonic function?
It's a chord's tendency — to move toward another chord or to stay at rest — and this text sorts chords into four functions. Harmonic function describes a chord's tendency: either to move toward another chord or to stay at rest. This text recognizes four functions (shown here in major):
| Function | Chords | Tendency |
|---|---|---|
| Tonic | I | Stable, at rest; does not demand progression |
| Tonic prolongation | iii, vi | Follow the tonic, then move toward pre-dominant |
| Pre-dominant | IV, ii | Move toward the dominant |
| Dominant | V, vii° | Tense; demand resolution to tonic (I) |
This can be summarized as a flow:
Tonic (I) → Tonic prolongation (iii / vi) → Pre-dominant (IV / ii) → Dominant (V / vii°) → Tonic (I)
Dominant chords contain the leading tone (7̂), so they strongly pull to tonic; pre-dominant chords contain degrees 4̂ and 6̂, which lead naturally to the dominant. Two exceptions to this flow are the plagal cadence (IV → I, where IV acts as tonic prolongation) and the deceptive cadence (V → vi).
Foundational progressions
- Tonic – Dominant – Tonic (T–D–T): the most elemental progression, usually I – V – I (or I – vii° – I). Countless pieces open this way.
- Tonic – Pre-dominant – Dominant – Tonic (T–PD–D–T): four common realizations — I – ii – V – I, I – IV – V – I, I – IV – vii° – I, and I – ii – vii° – I.
People often say "Rock 'n' Roll is just three chords: I, IV, and V" — and that's precisely because those three chords represent the three core functions: tonic (I), pre-dominant (IV), and dominant (V).
See Roman Numerals & Cadences and Seventh Chords for the fundamentals, and Non-Chord Tones for the melodic layer over these progressions.
Frequently asked questions
Why is it called a "circle of fifths"? Because each chord's root moves down a fifth (or up a fourth) from the one before, forming a chain of descending fifths that uses only diatonic notes.
What are the four harmonic functions? Tonic (I), tonic prolongation (iii, vi), pre-dominant (IV, ii), and dominant (V, vii°). They flow: tonic → tonic prolongation → pre-dominant → dominant → tonic.
Why does Rock 'n' Roll only need three chords, I, IV, and V? Because those three chords cover the three core functions — tonic (I), pre-dominant (IV), and dominant (V) — which is enough for a complete harmonic flow.