Introduction to Seventh Chords & Inversions
Seventh chords add richness and tension to music, making them essential in harmony. In AP Music Theory, you must understand:
- How to build seventh chords
- Inversions (1st, 2nd, 3rd inversion)
- Figured bass symbols
- Voice leading & resolution rules
Let’s break it all down!
1. What is a Seventh Chord?
A seventh chord is a triad + a seventh interval above the root. The four types tested in AP Music Theory are:
| Chord Type | Formula (from root) | Example (C) |
|---|---|---|
| Major 7th | 1 – 3 – 5 – 7 | C – E – G – B |
| Dominant 7th | 1 – 3 – 5 – ♭7 | C – E – G – B♭ |
| Minor 7th | 1 – ♭3 – 5 – ♭7 | C – E♭ – G – B♭ |
| Diminished 7th | 1 – ♭3 – ♭5 – ♭♭7 | C – E♭ – G♭ – B♭♭ (A) |
(Note: The dominant seventh (V7) is the most important in tonal harmony.)
2. Seventh Chord Inversions
Inversions rearrange the chord so the third, fifth, or seventh is in the bass.
| Inversion | Bass Note | Figured Bass | Chord Stack |
|---|---|---|---|
| Root Position | Root | 7 (or 7/5/3) | R – 3 – 5 – 7 |
| 1st Inversion | 3rd | 6/5 | 3 – 5 – 7 – R |
| 2nd Inversion | 5th | 4/3 | 5 – 7 – R – 3 |
| 3rd Inversion | 7th | 4/2 or 2 | 7 – R – 3 – 5 |
Examples in C Major:
- C7 (Dominant 7th)
- Root: C – E – G – B♭
- 1st Inv: E – G – B♭ – C (6/5)
- 2nd Inv: G – B♭ – C – E (4/3)
- 3rd Inv: B♭ – C – E – G (4/2 or 2)
3. Figured Bass for Seventh Chords
Figured bass tells performers which inversion to play.
| Chord Position | Figured Bass | Meaning |
|---|---|---|
| Root Position | 7 | 5th & 3rd are implied |
| 1st Inversion | 6/5 | 6th & 5th above bass |
| 2nd Inversion | 4/3 | 4th & 3rd above bass |
| 3rd Inversion | 4/2 or 2 | 4th & 2nd above bass |
Why is this important for AP Music Theory?
- You’ll see figured bass in melodic harmonization questions.
- Helps in Roman numeral analysis (e.g., V⁶₅, V₄₃).
4. Resolving Seventh Chords (Voice Leading Rules)
The 7th must resolve down by step, and the leading tone (if present) resolves up.
Dominant 7th (V7) → Tonic (I) Resolution
- V7 (G-B-D-F) → I (C-E-G)
- B (7th) → C (down)
- F (7th) → E (down)
- G (root) → C (or stays)
- D (5th) → G or E
Common Mistakes to Avoid:
❌ Parallel 5ths/Octaves (e.g., both voices moving the same way)
❌ Unresolved 7th (must resolve downward)
5. Practice Questions (AP Music Theory Style)
Multiple Choice:
- What is the figured bass for a dominant seventh chord in 2nd inversion?
- (A) 6/5
- (B) 4/3
- (C) 2
- (D) 7
Answer: B (4/3)
Free Response:
Analyze this progression in C Major:V₄₃ → I
- What notes are in the bass?
- How does the 7th resolve?
Answer:
- Bass: G (5th of V7) → C (root of I)
- 7th (F) resolves to E
6. Tips for Mastering Seventh Chords on the AP Exam
✅ Memorize figured bass symbols (7, 6/5, 4/3, 2).
✅ Practice writing inversions in all keys.
✅ Always resolve the 7th down in voice leading.
✅ Listen to chord resolutions (e.g., V7 → I cadence).
Conclusion
Seventh chord inversions are crucial for AP Music Theory success. By mastering:
✔ Chord construction
✔ Inversions & figured bass
✔ Voice leading rules
—you’ll ace harmony questions on the exam!
Need more help? Check out my [AP Music Theory Ultimate Guide] for extra practice!
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