Questions: Diatonic Harmonic Progression

Question 1

A student writes the progression I–IV–I–V–I and labels it poorly constructed because 'it interrupts the circle of fifths.' Their teacher disagrees. Why is the teacher correct?

• A. Circle of fifths progressions are required in all tonal music, so interrupting them is always a flaw
• B. The progression is functionally coherent — it traces tonic → predominant → tonic → dominant → tonic — and the circle of fifths is one useful pattern, not a compositional requirement
• C. The progression is actually a circle of fifths in disguise, played in retrograde
• D. There are no compositional rules, so no progression can be called poorly constructed

Answer: (B)

Functional coherence, not adherence to the circle of fifths, is the criterion for a well-constructed diatonic progression. I–IV–I–V–I follows a clear functional arc: tonic stability, predominant motion, return to tonic, dominant tension, resolution. Each move creates and fulfills expectations. The circle of fifths progression (iii–vi–ii–V–I) is a powerful pattern precisely because it chains functional expectations systematically — but it is one tool among many, not a rule.

Question 2

A composer wants to smooth out a choppy bass line in a I–IV–V–I progression where the bass keeps leaping between chord roots. What is the most common technique for achieving stepwise bass motion while preserving the harmonic progression?

• A. Remove the bass voice from the texture to eliminate the leaping problem
• B. Use first-inversion chords strategically to place the third in the bass, enabling smaller bass motion between chords
• C. Double the harmonic rhythm so chords change twice as fast
• D. Replace the progression with sustained pedal tones on the tonic

Answer: (B)

First inversion (e.g., I6) places the chord's third in the bass rather than the root. This allows the bass to move by step or smaller intervals between chords that would otherwise require large leaps between roots. In Bach chorales, the pattern I–I6–IV moves the bass through scale degrees 1–3–4, achieving smoother voice-leading without changing the harmonic logic in the upper voices.

Question 3

Prolonging the dominant harmony for several measures before resolving to tonic creates more tension than resolving immediately.

• T. True
• F. False

Answer: True

Dominant function creates an expectation of resolution to tonic — the longer that expectation is held unfulfilled, the more tension accumulates. This is why a sustained V or V7 before a final cadence feels urgent. Composers control tension by managing how long they dwell on each functional area. A dominant that resolves immediately feels declarative; one that is prolonged across a phrase feels like a withheld breath — and the eventual resolution is proportionally more satisfying.

Question 4

The progression I–IV–V–I is effective because these chords were randomly selected from the key; any four diatonic chords in any order would produce the same effect.

• T. True
• F. False

Answer: False

I–IV–V–I is effective because of its functional arc: tonic (stability) → predominant (motion away) → dominant (tension toward resolution) → tonic (arrival). Each function creates a specific expectation, and the sequence fulfills those expectations in a satisfying order. A random sequence of diatonic chords (e.g., I–iii–vi–IV) may be harmonically legal but lacks the directed momentum that makes I–IV–V–I feel like a complete statement.

Question 5

Why is controlling the pacing of the tonic–predominant–dominant–tonic arc the central skill in harmonic composition, rather than simply selecting correct diatonic chords?

Model answer: Any diatonic chord sequence is 'correct' in the sense of staying in key, but not all sequences create a meaningful harmonic journey. Each functional area (tonic, predominant, dominant) generates listener expectations about what comes next. The expressive power lies in how long each phase lasts and when tension is introduced or resolved — too fast a resolution feels rushed, too long on the dominant feels stalled. Controlling that pacing is what gives a progression its emotional character.

Think of the functional arc as a breath: inhale (tonic), move (predominant), tension (dominant), exhale (tonic). A progression where every breath is the same length and intensity feels mechanical. The composer's craft is varying the length, intensity, and timing of each phase — extending a dominant to build anticipation, returning briefly to tonic before a final push, or subverting the expected resolution entirely — to shape the listener's emotional experience.