Diagnosing a Doubled Leading Tone in a Student Chorale
You are reviewing a 16-measure four-voice chorale exercise submitted by a high school AP Music Theory student. The exercise is in G minor and ends with a Picardy third. In measure 10, the student writes a root-position V chord (D–F♯–A) with F♯ in the soprano and F♯ in the tenor; in measure 11, the chord resolves to root-position i (G–B♭–D), with G in the soprano and G in the tenor. The student also labels the preceding chord in measure 9 as 'iv6' even though the bass is E♭ and the upper voices are C–G–C. The student argues that the measure 10–11 motion is acceptable because 'the leading tone resolves up in both voices.' Your rubric penalizes parallel perfect octaves and doubled leading tones in dominant-to-tonic motions, but the student wants a written explanation before revising. You have one 20-minute conference slot.
1. The student claims the two F♯s are acceptable because each resolves up. Decide whether the mm. 10–11 progression meets the rubric. Identify the specific error(s) and explain the reasoning in a way the student can apply to another dominant–tonic cadence.
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No, the progression does not meet the rubric. The chord in m. 10 is a root-position V: D is the root, F♯ is the third, and A is the fifth. The student has doubled the third, F♯, in soprano and tenor. In this style, a root-position V normally doubles the root or fifth, not the leading tone. Both F♯s then resolve to G, so soprano and tenor move from a perfect octave to another perfect octave. The problem is not that resolving the leading tone upward is wrong; it is that two voices resolve the same tendency tone in parallel, producing parallel octaves. A transferable check is: label each chord member, identify which member is doubled, then compare the interval between the doubled voices before and after resolution. If the doubled member is the leading tone and both voices resolve up, the parallel octave is almost inevitable.
2. Evaluate the label 'iv6' in m. 9. If the chord is correctly spelled, what is its likely function, and how would you explain the label to the student?
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The label is correct if the key is still G minor. The iv chord is C minor, spelled C–E♭–G. With E♭ in the bass, the chord is in first inversion, so 'iv6' is the right Roman numeral. The upper voices C–G–C double the root C and include the fifth G; the third is in the bass. The student may be treating the bass note as the root and calling the chord E♭ major. Explain that in figured bass the '6' tells the performer that the third of the chord is in the bass. Functionally, iv6 is a predominant chord and often moves to V or V7. If it moves to V in G minor, the E♭ should resolve down to D, and the raised leading tone F♯ must appear in the dominant chord rather than being introduced early in the iv6.
3. Propose a two-step revision plan for the 20-minute conference that preserves the student's soprano line and explains the correction without simply giving the answer.
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Step 1: hearing before labeling. Have the student play only soprano and tenor on the piano in mm. 10–11 and name the interval on the V chord and then on the i chord. Ask what changed and what stayed the same. Step 2: constrain the revision. Keep the soprano F♯ resolving to G and the bass D resolving to G, then ask the student to choose a different chord member for the tenor so that the leading tone is no longer doubled. A likely solution is tenor F♯ down to D, holding D into the i chord; the student should then check the new interval between soprano and tenor. End by having the student state the rule in their own words and apply it to a fresh two-chord V–i example. This keeps the soprano line intact while making the student diagnose the error rather than copy a correction.