SATB harmonisation: fixing a draft without reharmonising
During a harmony exercise, a candidate harmonises an 8-bar melody in G major for SATB. The soprano melody is: bar 1 G–A–B–A; bar 2 G–E–D–D; bar 3 E–F-sharp–G–A; bar 4 B–A–G–G; bars 5–8 repeat bars 1–4 but end on G. The candidate’s Roman numerals are I–vi–IV–V–I–V–IV–I. The bass is G–E–C–D–G–D–C–G, one chord per bar. The alto in bar 4 is F-natural; the tenor in bars 6–7 moves A–B while the bass moves D–E. The candidate says the final cadence is ‘perfect because it ends on G’ and has not checked the melody’s F-sharp in bar 3. The teacher requires one corrected progression, not a full reharmonisation, and asks the candidate to sing the bass line while playing the melody.
1. Identify two harmonic or voice-leading errors in the draft, with bar numbers, and give a minimal correction for each.
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Error 1: bar 3 uses IV (C major) under a melody containing F-sharp. In G major F-sharp is the leading tone and is not in C major; the clash is audible on beat 2 and weakens the approach to bar 4. Minimal fix: change bar 3 to V (D major), which contains F-sharp and supports the line, or to vi if the melody notes fit. Error 2: bars 6–7 have parallel perfect fifths between tenor and bass: bass D–E with tenor A–B gives D–A (a perfect fifth) to E–B (a perfect fifth). Minimal fix: move the tenor from A to G, so D–A becomes E–G, or change the bass to B. A third issue is bar 4’s alto F-natural against V: it should be F-sharp, the leading tone, unless the candidate can justify a chromatic alteration. The two named errors are enough to show that the Roman numerals are not yet supported by the voices.
2. Assess the candidate’s claim that the final cadence is perfect. What must be true for a perfect authentic cadence, and what is actually happening in bars 7–8?
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A perfect authentic cadence needs a root-position V–I or V–i, both chords in root position, and the tonic in the soprano at the final chord. Here the final chord is G major with G in the soprano, which meets the soprano condition, but bar 7 is IV (C major), not V. So the progression is plagal (IV–I), not perfect authentic. The leading tone F-sharp also needs to resolve to G in an inner voice; the candidate’s alto F-natural in bar 4 shows they have not controlled the leading tone earlier. Minimal fix: change bar 7 to V (D major), preferably with F-sharp in an inner voice, then resolve to I in bar 8. If the melody in bar 7 contains E–F-sharp–G–A, V is a better fit than IV and removes the F-sharp clash.
3. Explain how singing the bass while playing the melody would help diagnose the errors, and state one thing the candidate should listen for.
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Singing the bass forces the candidate to hear the harmonic foundation as a line, not as a set of labels. When the bass moves D–E in bars 6–7 and the tenor moves A–B, the singer should hear the two voices moving in parallel fifths; that is hard to notice from Roman numerals alone. Playing the melody at the same time also exposes the bar 3 clash: the F-sharp in the melody against C in the bass will sound like a semitone friction that does not resolve. The candidate should listen for the leading tone F-sharp and whether it rises to G, and for the bass’s cadential approach: if the bass sings C–G at bars 7–8, the cadence will feel plagal, not perfect. This is a diagnostic, not a substitute for checking the score.