Questions: Chord Inversions and Voice-Leading Options

Question 1

A composer wants a bass line that moves by step across a I–V–I progression rather than leaping between chord roots. Which harmonic choice best achieves this?

• A. Use all three chords in root position — the natural bass notes will create smooth motion.
• B. Use I–V6–I, placing the third of V in the bass to create a stepwise bass of 1–7–1.
• C. Double the bass in the tenor voice to smooth out the leaps.
• D. Substitute vi for I in the final chord so the bass can descend stepwise to 6.

Answer: (B)

Root-position I–V–I has a bass of scale degrees 1–5–1, which jumps a fifth and a fourth. First inversion (V6) places the third — scale degree 7 — in the bass. The bass then moves 1–7–1, entirely stepwise. This is the core function of inversions as voice-leading tools: they free the bass from root-to-root leaps and allow it to move melodically. Option A is incorrect because root position always puts the chord root in the bass, forcing harmonic-interval motion regardless of doublings.

Question 2

Why does the cadential 6/4 chord require resolution to the dominant rather than being usable in any harmonic context?

• A. Because second-inversion chords have a louder, more assertive sound that overwhelms the tonic.
• B. Because the fourth above the bass is an unstable dissonance that the ear expects to resolve downward to the third and fifth of the dominant.
• C. Because music theory rules forbid the tonic chord from appearing in second inversion near a cadence.
• D. Because the 6/4 chord contains a tritone that must resolve by contrary motion to the dominant.

Answer: (B)

The cadential 6/4 places the tonic chord's fifth in the bass (second inversion). The interval of a fourth above the bass is an unstable dissonance in tonal voice-leading — the ear hears it as a suspended tone requiring downward resolution. Conventionally, the sixth and fourth above the bass resolve by step to the fifth and third of the dominant. This tension-then-resolution is why the cadential 6/4 amplifies an approach to a cadence rather than serving as a stable tonic. Unlike first-inversion chords, second-inversion chords carry inherent instability and cannot be placed freely.

Question 3

Using a first-inversion chord allows the bass voice to move by step rather than by the large leaps of fourths and fifths typical of root-position progressions.

• T. True
• F. False

Answer: True

In root position, the bass carries the chord root, so a I–V–I progression has a bass of scale degrees 1–5–1 — a leap of a fifth followed by a fourth. First inversion places the third in the bass. A I–V6–I progression produces a bass of 1–7–1 — completely stepwise. This stepwise motion is the defining advantage of first inversion as a voice-leading tool: it gives the bass access to non-root chord tones, enabling melodic, directed motion rather than harmonic leaps between chord roots.

Question 4

Second-inversion (6/4) chords are as stable as root-position chords and can be placed freely in any harmonic context without special preparation or resolution.

• T. True
• F. False

Answer: False

Second-inversion chords are inherently unstable due to the dissonant fourth above the bass, and classical voice-leading recognizes only three sanctioned uses: cadential, passing, and pedal 6/4 — each with specific preparation and resolution conventions. Treating 6/4 chords as stable and placing them freely produces unresolved dissonances. The instability is not a limitation but a resource: the cadential 6/4 exploits this tension deliberately to heighten the approach to a cadence.

Question 5

Why are inversions described as making the bass voice 'melodic,' and how does this differ from root-position writing?

Model answer: In root-position writing, the bass always carries the chord root, so its motion is governed by harmonic function — moving by fourths, fifths, and other large intervals between chord roots. Inversions place the third or fifth in the bass instead, allowing it to move by step or third. When the bass moves stepwise, it behaves like a melody: it has shape, direction, and smooth contour. The bass becomes an active contrapuntal voice rather than a harmonic anchor, and the texture gains a layer of interest that root-position writing cannot provide.

Baroque composers exploited this systematically, building structures over descending tetrachord bass lines (4–3–2–1 scale degree patterns). The stepwise bass is possible precisely because inversions put non-root tones in the bass at each step. When you hear a I–V6–vi–IV6–I progression, the bass descent (1–7–6–5–5) is what gives it its characteristic sound — and that descent is only achievable through inversions. Understanding inversions as melodic tools, not just harmonic labels, is the core skill of tonal voice-leading.