Questions: Seventh Chord Types and Their Qualities

Question 1

A composer wants a single chord that creates the strongest functional pull toward tonic resolution in tonal music. Which chord type should they use?

• A. Major seventh chord (maj7), because the major seventh adds lush richness that emphasizes the tonic
• B. Half-diminished seventh (m7♭5), because it is the most dissonant option and dissonance creates tension
• C. Dominant seventh (dom7), because the tritone between its third and seventh resolves by contrary motion toward the tonic
• D. Minor seventh (min7), because minor quality is inherently more tense than major

Answer: (C)

The dominant seventh chord is the engine of tonal harmony precisely because of its tritone — the interval between the third and seventh (e.g., B and F in G7). This tritone resolves inward by contrary motion (B up to C, F down to E), while the leading tone (B) simultaneously pulls upward to the tonic. No other seventh chord type produces this degree of directed urgency. The maj7 chord is actually quite stable and does not demand resolution; the m7♭5 is tense but lacks the same directed resolution mechanism.

Question 2

The chord C–E–G–B is which type of seventh chord?

• A. Dominant seventh (dom7), because it has a major triad with an added seventh
• B. Major seventh (maj7), because the seventh B is a major seventh interval above the root C
• C. Minor seventh (min7), because E–G spans a minor third
• D. Half-diminished seventh (m7♭5), because the chord contains a seventh

Answer: (B)

C–E–G is a major triad, and B is a major seventh above C (11 semitones). This combination — major triad + major seventh — defines the maj7 chord. The most common confusion is with the dominant seventh (dom7), which is also built on a major triad but uses a *minor* seventh (e.g., C–E–G–B♭ for C7). The interval between the seventh and the root is the key distinguishing factor: major seventh (11 semitones) = maj7; minor seventh (10 semitones) = dom7.

Question 3

A dominant seventh chord is built from a major triad with a major seventh added above the root.

• T. True
• F. False

Answer: False

This is the most common confusion between maj7 and dom7. A dominant seventh uses a *minor* seventh (10 semitones above the root), not a major seventh (11 semitones). For example, G7 is G–B–D–F: the F is a minor seventh above G. It is this combination of a major triad with a *minor* seventh that produces the tritone (B–F in G7) responsible for the chord's strong resolution tendency. Cmaj7 (C–E–G–B) has a major seventh and sounds lush and stable, not tense.

Question 4

The dominant seventh chord contains a tritone between its third and seventh, which is the primary source of its strong tendency to resolve.

• T. True
• F. False

Answer: True

The tritone (augmented fourth / diminished fifth) is the most unstable interval in tonal music. In a dominant seventh chord, it appears between the third (the leading tone) and the seventh. These two notes pull in opposite directions toward the tonic chord: the leading tone steps up to the tonic, and the seventh steps down — contrary motion that resolves the tritone inward. This double resolution mechanism is unique to the dominant seventh and accounts for its functional ubiquity in Western tonal music.

Question 5

Explain why the dominant seventh chord has such a strong tendency to resolve, in terms of the specific intervals it contains.

Model answer: The dominant seventh contains a tritone between its third and seventh (e.g., B and F in G7). The tritone is maximally unstable and resolves by contrary motion: the third (B, the leading tone) rises by semitone to the tonic (C), while the seventh (F) falls by semitone to the third of the tonic chord (E). This inward resolution of the tritone, combined with the upward pull of the leading tone, creates two simultaneous directed motions toward the tonic — making the V7→I motion the strongest cadential force in tonal harmony.

Understanding this mechanism — rather than just memorizing that V7 resolves to I — is what allows musicians to use and vary dominant harmony intelligently. Extensions, alterations, and substitutions all work by modifying or preserving this resolution mechanism.