Practice a College Board-style free response question on Harmony & Voice Leading II. Write your response, then reveal the model answer to see exactly what earns each point.
Free Response Question · Unit 5 · Predominant Function & Six-Four Chords
A phrase in C major uses the progression I – IV – I⁶₄ – V – vi. Use this information to answer the parts below. (No staff paper is needed — describe each answer in words, note names, and standard labels.)
A
Identify the harmonic function (tonic, predominant, or dominant) of each chord in the progression I, IV, and V. Explain the role of the I⁶₄ chord separately, since it is not simply "tonic."
✓ Model answer (earns the point)
I has tonic function, IV has predominant function, and V has dominant function. The I⁶₄ is a cadential six-four — although it is spelled like a tonic triad, it functions as an embellishment of the dominant that follows it, not as a genuine tonic arrival.
Why it scores: Correctly labels I, IV, and V by function AND explains that the I⁶₄ functions as dominant despite its spelling. Simply calling the I⁶₄ "tonic" without qualification loses the point.
B
The phrase ends V–vi instead of V–I. Name this cadence type and explain why vi is able to substitute for the expected chord.
✓ Model answer (earns the point)
This is a deceptive cadence. It works because vi shares two notes with I (in C major, vi is A–C–E, sharing C and E with the C major triad), making vi a tonic substitute that can stand in for the expected I while still resolving the dominant's tension.
Why it scores: Names the cadence (deceptive) AND explains vi's tonic-substitute quality via its shared tones with I. Just saying "V goes to vi instead" without the shared-tone reasoning earns only partial credit.
C
Describe how the upper voices of the I⁶₄ resolve into the following V chord. Name the two notes involved and the direction of motion.
✓ Model answer (earns the point)
In the I⁶₄ (G in the bass, with C and E above), the sixth above the bass (E) resolves down by step to D (the fifth of V), and the fourth above the bass (C) resolves down by step to B (the third of V, which is also the leading tone of the key). The bass stays on G throughout, since G is scale degree 5 in both the I⁶₄ and the following V.
Why it scores: Identifies both resolving voices (the 6th and the 4th above the bass) AND states they move down by step into the dominant, with the bass remaining stationary. Vague answers like "the notes just resolve" earn no point.
How to score points on AP Music Theory free response
Answer the exact verb. "Identify" wants a name; "explain" or "justify" wants the name plus the reasoning or rule behind it.
Distinguish spelling from function. A chord labeled I⁶₄ can still function as dominant — say so explicitly.
Explain shared tones for substitutions. "vi shares two notes with I" is the reasoning graders want for a deceptive cadence.
Name specific voices when describing resolution. "The 6th and 4th resolve down by step" is stronger than "the notes resolve."
Be concise and specific. A few precise sentences with correct terminology score higher than long, vague descriptions.