A chordal seventh is the note a seventh above the chord root, and it needs careful handling because it creates dissonance. The main rules: approach it by common tone or by step (leap only when you have to), and resolve it down by step.
Why This Matters for the AP Music Theory Exam
Seventh chords show up everywhere in tonal music, so being able to handle the chordal seventh correctly is a core part-writing skill. On the AP Music Theory exam, you use these rules in several ways: realizing chords in four-voice (SATB) textures from figured bass or Roman numerals, spotting voice-leading errors in a score, and recognizing how a dominant seventh pulls toward the tonic when you listen. Knowing how the chordal seventh approaches and resolves also helps with harmonic dictation and analysis, since a V7 resolving to I is one of the most common patterns you will hear and write.
Key Takeaways
- The chordal seventh is the note a seventh above the root and is what makes a seventh chord dissonant.
- Approach the chordal seventh by common tone or by step; use an ascending leap only when forced, and a descending leap of a third only rarely.
- Resolve every chordal seventh down by step to avoid an unresolved seventh.
- In a I-V⁴₃-I⁶ progression, the chordal seventh of the V⁴₃ can move up by step instead.
- The chordal seventh can be held (retained) in the same voice before resolving down.
- You may omit the fifth of a root-position V7 to smooth voice leading, but then double the root; inverted seventh chords must be spelled completely.
The Chordal Seventh
A seventh chord usually has four notes, each a third apart. The note a seventh above the root is the chordal seventh, and it is what makes a seventh chord a seventh chord. Because of that extra note, seventh chords come with special rules that triads do not need.
Often when people talk about the chordal seventh, they mean the chordal seventh of the V7 chord, which is scale degree 4. This note is a tendency tone, because it wants to resolve down to scale degree 3 (just like the leading tone wants to resolve up to the tonic). Unless something unusual is happening, you should resolve the chordal seventh down, especially when it is scale degree 4.
Why does the chordal seventh need so much attention? Think about a triad. It has three notes a third apart, and the intervals between them (perfect fifths, perfect fourths, thirds, sixths) are consonant. That makes triads relatively easy to arrange in progressions without worrying about harsh sounds.
Seventh chords are different. The chordal seventh introduces dissonances such as minor or major sevenths and other clashing intervals. That dissonance is the whole point of the sound, but it means you have to be careful about how the seventh gets approached and resolved.
Voice Leading With Chordal Sevenths
There are a few main conventions to follow when part-writing with seventh chords.
Approach the seventh smoothly. Chordal sevenths should almost always be approached by common tone or by step. For example, in A Major moving from the tonic chord to V7, the chordal seventh is D. You can reach that D from a step above (E) or a step below (C♯).
If voice-leading rules force your hand and you cannot approach the seventh by step or common tone, you may approach it by ascending leap or, rarely, by a descending leap of a third. Try to avoid that descending leap of a third whenever you can; an ascending leap is the better choice.
Resolve the seventh down by step. All chordal sevenths should resolve by a descending step to avoid an unresolved seventh. Using the example above, if you move from V7 to vi, the chordal seventh D should resolve down to C♯.
There are a couple of exceptions to the resolve-down rule:
- Retaining the seventh. The chordal seventh may be held in the same voice into the next chord before resolving down by step. This adds tension. For instance, when a dominant-function chord is followed by another dominant-function chord, a shared seventh can stay put before resolving, which helps prolong the dominant area before the eventual move to tonic.
- The I-V⁴₃-I⁶ progression. Here the chordal seventh of the V⁴₃ moves up by step instead of down, giving a 3-4-5 scale-degree line. This usually happens in a middle voice, not an outer voice.
Omitting the fifth. You may omit the fifth of a root-position dominant seventh chord if it helps the voice leading. When you do, double the root. Remember that all inverted seventh chords must be spelled completely, so this omission only applies in root position.
How to Use This on the AP Music Theory Exam
Part-Writing Tasks
When you realize seventh chords in SATB, check the chordal seventh first. Confirm it is approached by step or common tone (or a justified leap), then confirm it resolves down by step. A seventh that is approached or resolved incorrectly is one of the most common ways students lose voice-leading credit.
Build a quick habit:
- Find the chordal seventh in each seventh chord.
- Trace where it came from (step? common tone?).
- Trace where it goes (down by step, unless you are in I-V⁴₃-I⁶ or retaining it).
- Make sure root-position V7 chords either are complete or have the fifth omitted with the root doubled.
Error Detection
In a given score, scan for an unresolved seventh or a seventh that leaps where it should step. Also watch for inverted seventh chords that are missing a chord tone, since those must be complete.
Listening and Analysis
When you hear a V7 resolve, listen for that scale-degree 4 falling to scale-degree 3 along with the leading tone rising to tonic. Recognizing this gesture by ear supports harmonic dictation and Roman-numeral analysis.
Common Trap
The biggest trap is forgetting that inverted seventh chords cannot drop a note. The fifth-omission shortcut only works for root-position dominant seventh chords. Double-check inversions before you move on.
Common Misconceptions
- "You can always drop the fifth of a seventh chord." Only the fifth of a root-position dominant seventh chord can be omitted, and only if you double the root. Inverted seventh chords must include every chord tone.
- "The chordal seventh always resolves down." It almost always does, but in a I-V⁴₃-I⁶ progression the seventh moves up by step, and it can also be retained in the same voice before resolving down.
- "Any approach to the seventh is fine." The preferred approaches are by step or common tone. An ascending leap is a backup, and a descending leap of a third should be rare.
- "The chordal seventh is only in the V7 chord." Any seventh chord has a chordal seventh. The V7's seventh (scale degree 4) gets the most attention because it is a strong tendency tone, but the same rules apply to other seventh chords.
- "Dissonance from the seventh means the chord is wrong." The dissonance is intentional and characteristic. The point is to handle it correctly by approaching and resolving it properly, not to avoid it.
Related AP Music Theory Guides
Vocabulary
The following words are mentioned explicitly in the College Board Course and Exam Description for this topic.Term | Definition |
|---|---|
ascending leap | Movement upward by an interval larger than a step. |
common tone | A note that appears in both consecutive chords and can be retained in the same voice to create smooth voice leading. |
contextual listening | The practice of listening to and analyzing music within its historical and stylistic context. |
descending leap | Movement downward by an interval larger than a step. |
descending step | Movement downward to an adjacent lower scale degree. |
dominant seventh chord | A seventh chord built on the fifth scale degree of a key, typically used to create harmonic tension that resolves to the tonic. |
doubled | When a note appears in more than one voice in a chord. |
error detection | The identification of voice-leading mistakes or violations of compositional conventions in musical writing. |
fifth of a chord | The interval of a fifth above the root of a chord. |
four-voice texture | A musical arrangement consisting of four distinct voice parts or lines, typically organized as SATB. |
I-V⁴₃-I⁶ progression | A specific chord progression from tonic to dominant seventh in second inversion to tonic in first inversion. |
inverted seventh chord | A seventh chord with a note other than the root in the lowest voice. |
leap | A melodic interval larger than a step, traversing pitches that are not adjacent letter names. |
part-writing | The process of composing individual melodic lines for each voice in a multi-voice musical texture. |
root | The fundamental note of a chord upon which the chord is built. |
root-position seventh chord | A seventh chord with the root in the lowest voice. |
score analysis | The examination and study of musical scores to understand compositional techniques and voice-leading procedures. |
seventh chords | Chords built on a triad by adding a note a seventh above the root, creating four-note harmonies with specific qualities. |
step | A melodic interval that traverses adjacent pitches with neighboring letter names. |
V⁴₃ chord | A dominant seventh chord in second inversion, with the seventh in the bass and specific voice-leading conventions. |
voice leading | The technique of moving individual melodic lines (voices) in a musical composition, including considerations for smooth transitions and proper resolution of chords. |
Frequently Asked Questions
How do you voice lead seventh chords in AP Music Theory?
Find the chordal seventh, approach it by common tone or step when possible, and resolve it down by step unless a specific exception applies.
What is a chordal seventh?
A chordal seventh is the note a seventh above the chord root. It creates dissonance and usually needs to resolve carefully in part-writing.
How should a chordal seventh resolve?
A chordal seventh should usually resolve down by step. This avoids an unresolved seventh and supports standard 18th-century voice leading.
How should you approach a chordal seventh?
Approach a chordal seventh by common tone or by step if possible. If the context forces another option, an ascending leap or rare descending leap of a third may be used.
Can you omit the fifth in a seventh chord?
You may omit the fifth of a root-position dominant seventh chord if it helps voice leading, but you should double the root. Inverted seventh chords must be complete.
What is the V43 exception for chordal sevenths?
In a I-V43-I6 progression, the chordal seventh of the V43 can move up by step instead of resolving down.