The Sad Chord Progression

In a major key, change the IV chord from major to minor before returning home. In C, play C-F-Fm-C. The move from F major to F minor changes one note, yet that note creates one of popular music's clearest shifts in colour.

I IV iv I
1 borrowed chord
A A-flat G in C

same family

Play the changing noteI - IV - iv - I

The progression

Follow the arrows once, then use the player below to hear the loop.

See the one-note change

Chord	Notes	Scale-degree line
F major, IV	F A C	A is 6 in C major
F minor, iv	F A-flat C	A-flat is flat 6
C major, I	C E G	G is 5

F and C stay present while A falls by a semitone to A-flat. On the return to C, A-flat can continue down to G. Your ear hears both continuity and chromatic motion.

Where does minor iv come from?

C major normally contains F major. C minor contains F minor. Using F minor for a moment inside C major is an example of modal interchange: the major-key song borrows a chord from its parallel minor key.

The borrowed A-flat is outside C major, so it attracts attention. Because the surrounding notes move smoothly, the chord still connects naturally to the tonic.

Why does iv lead to I?

The motion is a minor plagal cadence: iv-I. It does not use the leading tone B that powers G7-C. Instead, its strongest cue is the chromatic descent from scale degree 6 to flat 6 to 5.

Compare these endings:

IV-I: F-C. A diatonic plagal return with a broad, stable sound.

iv-I: Fm-C. A chromatic plagal return with A-flat leaning down to G.

V-I: G-C. A dominant return led by B rising to C and the bass moving G-C.

All three reach the tonic, but they create different approaches.

A focused listening exercise

Play C-F-Clearn the plain major plagal motion.
Play C-Fm-Chear the borrowed chord without the major IV first.
Play C-F-Fm-Cfollow A-A-flat-G in the upper voice.
Move that line to an inner voicenotice that the effect remains even when it is less exposed.

Timing controls the impact

Use iv once near an ending. A rare borrowed chord can mark the emotional turn of a lyric or the final line of a chorus.

Hold it longer. Extra time on iv makes the chromatic colour more explicit and delays the tonic.

Pass through it quickly. F-Fm-C in a single bar turns the change into a voice-leading gesture.

The chord does not carry one fixed emotion. Register, tempo, melody and context decide whether it sounds tender, dramatic, nostalgic or uneasy.

Useful variations

Add the sixth
Fm6 contains F, A-flat, C and D. In C major, D can move to E while A-flat moves to G, giving two smooth lines into the tonic.
Place scale degree 3 in the melody
Hold E over Fm for a sharper colour, then keep or resolve it when C arrives.
Use iv without IV first
Moving directly from I to iv makes the borrowed sonority more sudden.

Write with the line, not only the symbol

Begin with the melody A-A-flat-G. Harmonise it with F-Fm-C. Then write a different bass or inversion underneath. Starting from the moving voice helps the progression feel connected to the melody rather than added as an effect afterward.

When it is useful

Use minor iv when a major-key section needs one clear chromatic turn without changing key. It works especially well before a structural arrival because the voice leading points directly into the tonic.

Keep going

Everything in chord progressions

Open chord progressions