What is the I-V-vi-IV progression?

The most common chord progression in pop music, also called the "Axis progression" after the Axis of Awesome medley that strung dozens of hits on it. Songs from the Beatles' "Let It Be" to Journey's "Don't Stop Believin'" use it. In C: C-G-Am-F.

The minor-start variant of the Axis progression. Creates a more melancholic/dramatic feel. Starting on the minor chord gives a different emotional color while using the same four chords. In C: Am-F-C-G.

What are the three chord functions?

Tonic (home/rest: I, iii, vi), Subdominant (departure: ii, IV), Dominant (tension/pull home: V, vii°). Understanding function lets you substitute chords while maintaining the emotional journey.

Why does the Axis progression (I-V-vi-IV) work harmonically?

It visits all three chord functions in four chords: tonic (I), dominant (V), a tonic substitute (vi, which shares two notes with I), and subdominant (IV), then loops. V never goes home to I; it goes to vi instead, so the loop keeps circling rather than ending, which is why it can run under a whole song.

What is harmonic rhythm?

How often the chords change. Faster harmonic rhythm (chords changing every beat) creates urgency. Slower (every 2-4 bars) creates spaciousness. Accelerating harmonic rhythm is a powerful tool for building pre-choruses.

What is a borrowed chord?

A chord taken from the parallel key (e.g., using iv from C minor while in C major). The most common: IV → iv (major to minor IV). Creates a bittersweet, unexpected color.

What are the most common borrowed chords in pop?

iv (minor IV): bittersweet color. bVI: dramatic, cinematic. bVII: rock power, modal flavor. bIII: mysterious, otherworldly. These four are the ones you will meet most often in pop and rock.

What is the "backdoor cadence"?

iv7 to bVII7 to I: in C, Fm7 to Bb7 to C. The bVII7 is a dominant-seventh chord that arrives home from a whole step below instead of from V, so the resolution feels warmer and less expected. It is a jazz and standards device. Rock's plain bVII to I (Bb to C, Mixolydian) is a different thing, a modal move with no dominant seventh and no iv before it.

Which note makes a secondary dominant pull?

Its third, which is the leading tone of the chord it points at. D7 in C carries F sharp, a half step below G, so it pulls to G. E7 carries G sharp, a half step below A, so it pulls to A minor. To spot one by ear, listen for a major chord where the key would normally put a minor one (E instead of Em in C) and hear where it wants to go.

What are "passing chords"?

Chords used briefly between two structural chords to create smooth motion. Often chromatic (C - C#dim - Dm). They add elegance and sophistication without changing the fundamental harmonic structure.

Songwriting · concept guide

Chord Progressions for Songwriters: Function, the Axis Progression, and Borrowed Chords

Why I-V-vi-IV works, the three chord functions underneath every progression, harmonic rhythm, borrowed chords and the backdoor cadence, and a drill that has you name progressions by ear.

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Chord Progression ID

Hear the four chords under half the songs you know.

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Most songwriters know a handful of progressions by sound and none by function, which is why the handful never grows. Function is the idea that every chord is doing one of three jobs, home, departure or tension, and that the same job can be done by several chords. Once you hear the job rather than the chord, I-V-vi-IV stops being a progression to copy and becomes a shape you can vary: swap the departure, delay the return, borrow the tension from the parallel minor, and keep the shape the listener already trusts.

The drill above plays a progression and asks you to name it, which builds the ear that hears function. The cards cover the axis progression and its minor-start variant, the three functions, harmonic rhythm, borrowed chords and the most common ones in pop, the backdoor cadence, secondary dominants for forward motion, passing chords, the power-ballad trick, and modal interchange in plain terms.

The concepts

10 cards from the Songwriting deck

1
What is the I-V-vi-IV progression?
The most common chord progression in pop music, also called the "Axis progression" after the Axis of Awesome medley that strung dozens of hits on it. Songs from the Beatles' "Let It Be" to Journey's "Don't Stop Believin'" use it. In C: C-G-Am-F.
2
What is vi-IV-I-V?
The minor-start variant of the Axis progression. Creates a more melancholic/dramatic feel. Starting on the minor chord gives a different emotional color while using the same four chords. In C: Am-F-C-G.
3
What are the three chord functions?
Tonic (home/rest: I, iii, vi), Subdominant (departure: ii, IV), Dominant (tension/pull home: V, vii°). Understanding function lets you substitute chords while maintaining the emotional journey.
4
Why does the Axis progression (I-V-vi-IV) work harmonically?
It visits all three chord functions in four chords: tonic (I), dominant (V), a tonic substitute (vi, which shares two notes with I), and subdominant (IV), then loops. V never goes home to I; it goes to vi instead, so the loop keeps circling rather than ending, which is why it can run under a whole song.
5
What is harmonic rhythm?
How often the chords change. Faster harmonic rhythm (chords changing every beat) creates urgency. Slower (every 2-4 bars) creates spaciousness. Accelerating harmonic rhythm is a powerful tool for building pre-choruses.
6
What is a borrowed chord?
A chord taken from the parallel key (e.g., using iv from C minor while in C major). The most common: IV → iv (major to minor IV). Creates a bittersweet, unexpected color.
7
What are the most common borrowed chords in pop?
iv (minor IV): bittersweet color. bVI: dramatic, cinematic. bVII: rock power, modal flavor. bIII: mysterious, otherworldly. These four are the ones you will meet most often in pop and rock.
8
What is the "backdoor cadence"?
iv7 to bVII7 to I: in C, Fm7 to Bb7 to C. The bVII7 is a dominant-seventh chord that arrives home from a whole step below instead of from V, so the resolution feels warmer and less expected. It is a jazz and standards device. Rock's plain bVII to I (Bb to C, Mixolydian) is a different thing, a modal move with no dominant seventh and no iv before it.
9
Which note makes a secondary dominant pull?
Its third, which is the leading tone of the chord it points at. D7 in C carries F sharp, a half step below G, so it pulls to G. E7 carries G sharp, a half step below A, so it pulls to A minor. To spot one by ear, listen for a major chord where the key would normally put a minor one (E instead of Em in C) and hear where it wants to go.
10
What are "passing chords"?
Chords used briefly between two structural chords to create smooth motion. Often chromatic (C - C#dim - Dm). They add elegance and sophistication without changing the fundamental harmonic structure.

These are knowledge cards from the Songwriting deck. In the daily plan each one comes back as a quiz, spaced over weeks, so it stays known rather than read once.

The plan

Reading this once is not the same as being able to do it.

A daily session schedules the drill above at your level, quizzes these cards until they stick, and moves you on when you are ready. Twenty minutes a day, in the browser.

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