Harmonising a melody and voice leading: WACE Year 12 Music
“Harmonise a melody using appropriate chords, cadences and voice-leading conventions as part of composing and arranging”
Harmonising a melody means choosing a chord for each important melody note (the note should usually be a member of the chord), planning the cadences first to give the phrase shape, and connecting the chords with smooth voice leading: keep common notes, move other voices by the smallest step, and avoid parallel fifths and octaves. The result should support the melody and confirm the key without awkward jumps.
What this dot point is asking
SCSA wants harmonisation that is correct, idiomatic and smoothly voiced. The reliable approach works backwards from the cadences and forwards by good voice leading.
Choosing chords
For each strong beat, the melody note tells you which chords fit, because that note should normally belong to the chord. A melody note of C could be harmonised by C major (root), F major (fifth) or A minor (third). Choose among the options to make a good progression, favouring strong root movement (down a fifth, as in V to I and ii to V) and clear functional motion from tonic to subdominant to dominant and home.
Plan the cadences first
Cadences give a phrase its punctuation, so decide them before filling the middle:
- End a final phrase with a perfect cadence (V to I).
- End an opening or middle phrase with an imperfect cadence (ending on V) to sound unfinished.
- Use plagal or interrupted cadences for variety where the melody allows.
With the cadences fixed, harmonise the rest of the phrase to lead naturally into them.
The cadence points are the load-bearing chords. Decide them first, then harmonise the notes leading up to each cadence so the progression drives toward it. This stops the harmony from wandering and guarantees each phrase resolves convincingly.
Voice-leading conventions
In four-part (SATB) writing the way voices move between chords matters as much as the chords themselves:
- Keep any common note in the same voice.
- Move the other voices by the smallest possible interval, usually by step.
- Keep voices within their ranges and avoid voice crossing.
- Resolve the leading note up to the tonic, especially at a perfect cadence.
- Avoid consecutive (parallel) fifths and octaves between any pair of voices, the classic voice-leading error.
These conventions produce a smooth, singable inner texture rather than a series of disconnected block chords.
Step 1: write out the two chords
In C major, V is G B D and I is C E G. List the notes so you can see which are shared and which must move.
Step 2: keep the common tone
The note G is common to both chords, so keep G in the same voice. Holding common tones is the first principle of smooth voice leading.
Step 3: move the remaining voices by step
The leading note B rises by step to C (resolving the leading note up, as a perfect cadence requires), and D falls by step to C or to E. No voice leaps unnecessarily.
Step 4: check for parallels
Verify that no pair of voices moves in parallel fifths or octaves between the two chords. With the common tone held and the others moving by step, the cadence is clean: a textbook perfect cadence.
Adapting to style
Strict four-part rules suit a chorale or Western Art Music task. For jazz or contemporary harmonisation, the principles loosen: extended chords (sevenths and ninths), parallel motion and chord symbols over a groove are idiomatic. Match the harmonisation conventions to the style the task asks for.
Why this matters for the exam
Harmonisation tests whether you understand how harmony supports melody and how voices connect. A student who plans cadences and leads voices smoothly produces clean, convincing harmony; one who picks chords at random and leaps voices around creates parallels and awkward gaps that cost marks. This skill also strengthens the harmonic dictation and analysis questions.
- Parallel fifths and octaves
- The most penalised error in four-part writing. Check each pair of voices between consecutive chords.
- Not resolving the leading note
- At a perfect cadence the leading note should rise to the tonic; leaving it hanging weakens the cadence.
- Choosing chords the melody note does not fit
- The melody note should normally be a member of its chord on strong beats.
- Ignoring the cadences
- Planning the middle before the cadences leads to phrases that do not resolve. Fix the cadences first.
Exam-style questions
Questions in the style of SCSA exam questions on this dot point, each with a worked answer. They are written by ExamExplained unless tagged "Past paper"; the year shows the paper a question is modelled on.
WACE 2022-style8 marksHarmonise the given eight-bar melody in D major in four parts (SATB). Plan a perfect cadence at the final phrase end and an imperfect cadence at the mid-point, label your chords with Roman numerals, and observe voice-leading conventions.Show worked answer →
Work from the cadences outward, then voice the chords smoothly.
Cadences first: fix a perfect cadence (V to I, A major to D major) at the end and an imperfect cadence (ending on V, A major) at the mid-point. These load-bearing chords anchor the harmonisation.
Choose chords: on each strong beat pick a chord that contains the melody note, favouring strong root movement (down a fifth) and clear tonic-subdominant-dominant motion. Label each with Roman numerals (I, IV, V, ii, vi).
Voice leading: keep common tones in the same voice, move others by step, resolve the leading note (C sharp) up to D at the perfect cadence, and check every adjacent pair of voices for consecutive fifths and octaves. Markers most heavily penalise parallel fifths and octaves and an unresolved leading note, so check these explicitly.
WACE 2021-style5 marksDemonstrate smooth voice leading from V to I in C major in four parts, and explain each voice's movement. Identify the most commonly penalised voice-leading error and how you avoid it.Show worked answer →
In C major, V is G B D and I is C E G. Connect them by keeping the common tone and moving the rest by step.
Voice movement: keep G common to both chords in the same voice; the leading note B rises by step to C; D falls by step to C (or to E); the bass moves G to C. No voice leaps unnecessarily and the leading note resolves up, giving a clean perfect cadence.
Most penalised error: consecutive (parallel) fifths and octaves between any pair of voices. Avoid them by checking each adjacent pair of voices between the two chords; if two voices a fifth or octave apart move in the same direction to another fifth or octave, rewrite one of them by contrary or oblique motion. Markers reward the named error and a concrete avoidance method.