Major triad + minor seventh; contains tritone driving resolution to tonic.
Dominant Seventh Chord
The Dominant Seventh chord is the cornerstone of functional harmony.
It defines tension and release — the magnetic pull from instability to resolution.
Every authentic cadence, blues progression, and jazz turnaround relies on this chord’s internal friction between its major third and minor seventh.
Structure
A Dominant Seventh is built from a major triad with a minor seventh stacked above.
Formula:
Root – Major 3rd – Perfect 5th – Minor 7th
Semitone steps from root: 0 – 4 – 7 – 10
Example (G7):
G – B – D – F
| Interval | Distance | Note | Function |
|---|---|---|---|
| Root | 0 | G | Tonal anchor |
| Major 3rd | +4 | B | Defines brightness and drive |
| Perfect 5th | +7 | D | Reinforces stability |
| Minor 7th | +10 | F | Creates dominant tension |
The Tritone
The real power of the dominant seventh lies in the tritone between the 3rd and 7th.
In G7, the interval between B (3rd) and F (7th) spans six semitones — a dissonant, unstable interval that resolves predictably:
- The 3rd (B) rises by semitone → C (tonic root)
- The 7th (F) falls by semitone → E (major 3rd of tonic)
This opposing motion forms the perfect V → I cadence (G7 → C).
Roman Numeral Function
| Scale Degree | Function | Typical Resolution |
|---|---|---|
| V7 | Dominant of the key | Resolves to I or i |
| V7/V | Secondary dominant | Resolves to another dominant |
| ♭VII7 | Modal / mixolydian dominant | Often returns to I (rock/funk use) |
Dominant sevenths are therefore the pivot chords of tonal harmony — they point clearly toward the next destination.
Inversions
| Inversion | Notes (G7) | Symbol | Bass Note | Function |
|---|---|---|---|---|
| Root Position | G–B–D–F | G7 | G | Full tension, cadential strength |
| 1st Inversion | B–D–F–G | G7/B | B | Used in smooth bass lines |
| 2nd Inversion | D–F–G–B | G7/D | D | Light passing motion |
| 3rd Inversion | F–G–B–D | G7/F | F | Pulls strongly to tonic |
Sound and Character
- Mood: bold, tense, expectant
- Quality: bright yet unstable
- Function: dominant — creates forward harmonic motion
- Cadence effect: strongest in Western music (V7–I)
The chord’s major triad plus minor seventh forms a sonic duality: brightness (major) combined with tension (minor seventh).
Common Progressions
| Progression | Function | Example (in C) |
|---|---|---|
| V7 → I | Perfect cadence | G7 → C |
| ii7 – V7 – I | Jazz turnaround | Dm7 – G7 – Cmaj7 |
| V7/ii → ii7 | Secondary dominant | A7 → Dm7 |
| I7 – IV7 – V7 | Blues cycle | C7 – F7 – G7 |
| ♭VII7 → I | Rock / modal | B♭7 → C |
Usage
- Classical: closes cadences, defines key relationships
- Blues: tonic chord itself is often dominant (I7)
- Jazz: nearly every progression features V7 movement
- Pop/Rock: borrowed as modal color or transitional chord
Real-World Examples
| Song | Artist | Key / Use |
|---|---|---|
| “Hound Dog” | Elvis Presley | Blues in C – I7, IV7, V7 cycle |
| “Georgia on My Mind” | Ray Charles | G7 resolves to Cmaj7 |
| “All Blues” | Miles Davis | Modal blues built on dominant 7ths |
| “Let’s Stay Together” | Al Green | V7 chords add soulful transitions |
| “Hey Joe” | Jimi Hendrix | Chained V7 progression descending by fifths |
Application Tips
- To build one: take a major triad and lower the 7th by a semitone.
- Use V7 → I for closure, or chain dominants for tension (e.g., E7 → A7 → D7 → G7 → C).
- Add extensions (9, 13, ♯11) for jazz and fusion flavor.
- On guitar, dominant 7th grips (E7, A7, D7, G7, C7) form the backbone of blues.
Summary
| Attribute | Value |
|---|---|
| Formula | 1 – 3 – 5 – ♭7 |
| Semitones | 0 – 4 – 7 – 10 |
| Tonality | Major with tension |
| Emotional Color | Strong, gritty, energetic |
| Function | Dominant, cadential |
| Inversions | Four possible |
| Common Progressions | ii7–V7–I, I7–IV7–V7 |
| Used In | Classical, blues, jazz, rock, pop |