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

The most common chord progression in pop music, also called the "Axis progression." Used in hundreds of hits from The Beatles to Calvin Harris. 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.

How does the "Axis of Awesome" work harmonically?

The I-V-vi-IV progression works because it cycles through all three chord functions (Tonic→Dominant→Tonic Substitute→Subdominant) creating a complete emotional journey in four chords.

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 cover 90% of borrowed chords in popular music.

What is the "Backdoor Cadence" (bVII-I)?

Arriving at the tonic from the bVII chord instead of the expected V. Creates a warmer, more unexpected resolution. Used extensively in Beatles songs and jazz standards.

How do secondary dominants create forward motion?

A secondary dominant "tonicizes" the next chord by treating it temporarily as a tonic. V/V (D7 in C) creates a strong pull to V (G). This adds harmonic momentum and sophistication.

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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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." Used in hundreds of hits from The Beatles to Calvin Harris. 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
How does the "Axis of Awesome" work harmonically?
The I-V-vi-IV progression works because it cycles through all three chord functions (Tonic→Dominant→Tonic Substitute→Subdominant) creating a complete emotional journey in four chords.
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 cover 90% of borrowed chords in popular music.
8
What is the "Backdoor Cadence" (bVII-I)?
Arriving at the tonic from the bVII chord instead of the expected V. Creates a warmer, more unexpected resolution. Used extensively in Beatles songs and jazz standards.
9
How do secondary dominants create forward motion?
A secondary dominant "tonicizes" the next chord by treating it temporarily as a tonic. V/V (D7 in C) creates a strong pull to V (G). This adds harmonic momentum and sophistication.
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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