What distinguishes a dominant seventh chord (7) from a major seventh chord (Maj7)?
AA major triad with a minor seventh vs. a major triad with a major seventh
BA minor triad with a major seventh vs. a major triad with a minor seventh
CBoth use major triads; they differ only in the root note
DThe dominant seventh uses a diminished fifth; the major seventh uses a perfect fifth
The dominant seventh (e.g., G7) is built from a major triad + minor seventh. The major seventh (e.g., Gmaj7) is built from a major triad + major seventh — the top interval is a half-step higher. This difference in the seventh is what gives the dominant seventh its strong pull toward resolution and the major seventh its floating, stable quality.
Question 2 True / False
A fully diminished seventh chord (°7) is built entirely from stacked minor thirds, meaning every adjacent pair of notes is the same interval apart.
TTrue
FFalse
Answer: True
The fully diminished seventh stacks three minor thirds (3 semitones each): root → minor third → diminished fifth → diminished seventh. This symmetry divides the octave into four equal parts, which is why diminished seventh chords can be enharmonically respelled and reinterpreted in multiple keys.
Question 3 Short Answer
Why does the dominant seventh chord (V7) create such strong harmonic tension that resolves naturally to the tonic?
Think about your answer, then reveal below.
Model answer: It contains a tritone — the dissonant interval between its third and seventh — which resolves by contrary motion: the third rises a half-step to the tonic while the seventh falls a half-step to the third of the tonic chord.
In the key of C major, the G7 chord contains B (the third) and F (the seventh), which form a tritone. B wants to rise to C and F wants to fall to E — the two notes move in opposite directions toward the tonic chord. This contrary resolution is the source of the V7–I cadence's strong sense of arrival.