Performing Harmonic Analysis Using the Phrase Model
The phrase model — Tonic (T) → Predominant (PD) → Dominant (D) → Tonic (T) — is a conceptual map for understanding how chords group into functional zones within a phrase. Performing harmonic analysis means not just labeling individual chords with Roman numerals but identifying which functional zone each chord belongs to and how the zones flow from phrase opening to phrase ending. A chord's function is determined not only by its Roman numeral but by its position in the phrase and its voice-leading behavior.
A practical workflow: (1) identify the cadence first, since it anchors the phrase ending and reveals the key; (2) locate the opening tonic harmony; (3) find the predominant area in the middle, where harmonies begin moving away from tonic; (4) trace the dominant arrival that precedes the cadence. Multiple chords can occupy a single functional zone — for example, I → V⁶ → I⁶ all prolong the tonic zone, while IV → ii⁶ → ii both belong to the predominant zone.
Pay particular attention to bass-line motion: a descending bass line (5̂–4̂–3̂–2̂–1̂ or its partial version) often maps onto a T–PD–D–T succession. Watch for voice-leading exceptions: some chords appear out of "textbook" order in real music, especially when composers use prolongation techniques, deceptive cadences, or phrase extensions. The phrase model is a guide, not a formula — its value lies in revealing the underlying logic that makes a phrase feel like a complete, directed musical thought.