Seventh chords are chords that include a seventh interval added to the basic triad, creating richer and more complex harmonies. They are essential in many music genres, including jazz, blues, rock, and classical, providing emotional depth and smooth voice leading.
- Constructed by adding a seventh note above the root to a triad (root, third, fifth).
- Common types: Major seventh, minor seventh, dominant seventh, half-diminished, and fully diminished.
- Seventh intervals can be major (11 semitones) or minor (10 semitones), depending on the chord type.
- Major seventh (Δ7): Major triad + major seventh.
- Minor seventh (m7): Minor triad + minor seventh.
- Dominant seventh (7): Major triad + minor seventh.
- Half-diminished (m7♭5): Diminished triad + minor seventh.
- Fully diminished (°7): Diminished triad + diminished seventh.
Major Seventh Chords
A major seventh chord consists of a major third, perfect fifth, and major seventh.
Major seventh chords combine a major triad with a major seventh interval, giving a smooth, sophisticated sound often found in jazz and pop ballads.
- Symbol: Δ7 or maj7.
- Formula: 1 - 3 - 5 - 7 (where 7 is a major seventh).
- Example: CΔ7 = C - E - G - B.
C - E - G - B is a major seventh chord.
Minor Seventh Chords
A minor seventh chord includes root, minor third, perfect fifth, and minor seventh.
Minor seventh chords add a minor seventh to a minor triad, creating a warm, mellow sound used extensively in R&B, soul, and jazz.
- Symbol: m7.
- Formula: 1 - ♭3 - 5 - ♭7.
- Example: Cm7 = C - Eb - G - Bb.
Cm7 consists of C - Eb - G - Bb.
Dominant Seventh Chords
A dominant seventh chord uses a major triad plus a minor seventh.
Dominant seventh chords feature a minor seventh added to a major triad, generating tension that typically resolves to a tonic chord.
- Symbol: 7.
- Formula: 1 - 3 - 5 - ♭7.
- Example: G7 = G - B - D - F.
G7 includes G - B - D - F.
Half-Diminished Chords
Half-diminished chords combine a diminished triad with a minor seventh.
Half-diminished chords have a diminished triad plus a minor seventh, producing a tense, unresolved sound common in minor keys.
- Symbol: m7♭5 or ø7.
- Formula: 1 - ♭3 - ♭5 - ♭7.
- Example: Bm7♭5 = B - D - F - A.
Fully Diminished Chords
Fully diminished seventh chords use root, minor third, diminished fifth, and diminished seventh.
Fully diminished chords stack minor thirds, adding a diminished seventh (9 semitones above the fifth), creating maximal tension.
- Symbol: °7.
- Formula: 1 - ♭3 - ♭5 - ♭♭7 (diminished seventh).
- Example: C°7 = C - Eb - Gb - Bbb (A).
Seventh Chord Summary
| Chord Type | Symbol | Formula | Example (C root) | Sound/Use |
|---|---|---|---|---|
| Major Seventh | Δ7/maj7 | 1 - 3 - 5 - 7 | C - E - G - B | Smooth, jazzy, sophisticated |
| Minor Seventh | m7 | 1 - ♭3 - 5 - ♭7 | C - Eb - G - Bb | Warm, mellow, soulful |
| Dominant Seventh | 7 | 1 - 3 - 5 - ♭7 | C - E - G - Bb | Tense, resolving (#V7) |
| Half-Diminished | m7♭5/ø7 | 1 - ♭3 - ♭5 - ♭7 | C - Eb - Gb - Bb | Tense, unresolved |
| Fully Diminished | °7 | 1 - ♭3 - ♭5 - ♭♭7 | C - Eb - Gb - A | Maximal tension |
Conclusion
Seventh chords expand basic triads with extra tones, providing new colors and emotional nuances in music.
- They are built by adding a seventh interval (major, minor, or diminished) to triads.
- Common types include major seventh, minor seventh, dominant seventh, half-diminished, and fully diminished.
- Mastering seventh chords is key for understanding and creating rich harmonic progressions.