Harmony
Subdominant
The subdominant is the fourth degree of a key and the chord built on it (IV), which moves the music away from the tonic and often prepares the dominant, like F in C major.
What is the subdominant?
The subdominant is the fourth degree of the scale. In C major it is F and the F chord, written IV; in G major, C; in D major, G; in A minor, Dm, written iv.
The name does not mean "just below the dominant" on the neck. It comes from symmetry: the dominant is a fifth above the tonic (G above C), the subdominant a fifth below it (F below C).
What does the subdominant do in a progression?
It is the chord of departure. The tonic is rest, the dominant is tension, and the subdominant is the move away between them. The tonic, subdominant, dominant, tonic pattern (T-S-D-T) shapes thousands of songs: C F G C.
The ii chord shares this role: Dm contains F and A, two notes of F. That is why C Dm G C and Dm7 G7 Cmaj7 sound like variants of C F G C. In the I-V-vi-IV progression (C G Am F), the IV at the end of the cycle opens things up and relaunches the loop.
How to play I to IV on guitar
In C major: C (x32010) then F (133211), or the easier Fmaj7 (xx3210). In G major: G (320003) then C (x32010). In A major: A (x02220) then D (xx0232).
Fretboard shortcut: if the tonic root is on the 6th string, the subdominant is at the same fret on the 5th string. G at the 3rd fret of the 6th string, C at the 3rd fret of the 5th. From the 5th string, same thing on the 4th: C at fret 3, F at fret 3 (shape xx3211).
Try this: play A7 D7 A7 E7, the core of a blues in A, then the plagal cadence F to C, the famous amen ending of gospel and hymns.
Which subdominant variations should you use?
- Coloured IV: Fmaj7 (xx3210) or Fadd9 for a softer sound.
- ii: Dm7 (xx0211) before G7, the jazz standard move.
- Minor iv: Fm (133111), borrowed from the parallel minor, then C. The bittersweet effect is instant and common in pop and 60s ballads.
- IV over I: F with C in the bass (x33211) to keep the bass still.
Compare these colours in the chord progressions by style, where every degree, IV and ii included, is shown in Roman numerals. To place IV among the seven scale degrees, always count from the tonic.
Key takeaways
- The subdominant is degree IV, a fifth below the tonic (F in C).
- It moves away from the tonic and prepares the dominant: T-S-D-T, C F G C.
- ii (Dm) shares its function; minor iv (Fm) is a borrowed variant.
- On the neck: IV sits at the same fret, one string higher than the tonic root (except across the 3rd and 2nd strings).
Frequently asked questions
Why is it called the subdominant?
It does sit one step below the dominant, but the name mainly reflects symmetry around the tonic: the dominant is a fifth above, the subdominant a fifth below. The two frame the tonic on the circle of fifths.
What is the difference between IV and ii?
Both have subdominant function and share two notes (F and A in C). IV is brighter and more direct, typical of rock and folk; ii is softer and leads smoothly to V7, typical of jazz.
What is a plagal cadence?
It is the move from IV to I, for example F to C or D to A. Gentler than V to I, it is nicknamed the amen cadence because it ends so many hymns, and you hear it at the end of many pop and rock songs.
Related terms
Practise in the workshop
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