Definition
A vocal harmony can move in two ways relative to the melody:
- parallel: it follows the melody with the same rhythm and at a (nearly) constant distance, for example always a third above. This is the sound of the “duet” and of vocal-group harmonies.
- independent: it has its own contour, often in contrary or oblique motion, and sometimes a different rhythm. It comes from counterpoint and choral writing.
Most arrangements mix the two approaches.
Parallel harmony
- Diatonic: the distance follows the scale (major and minor thirds depending on the scale degree). In C major, melody C–D–E–F–G with a third above: E–F–G–A–B.
- Chromatic / exact: the distance stays identical in semitones (always a major third). It produces out-of-key notes: used for effects (planing, “spectral” choirs) or in modal contexts.
- Typical intervals: thirds and sixths (sweet), fourths and fifths (powerful, archaic, rock), octaves (weight).
- Strengths: simple to sing, immediate, very clear lyrics (all voices say the same syllables together).
- Risks: monotony; harmonized notes that contradict the chord; parallel fifths and octaves that fuse the voices (in pop often intended, in classical choir avoided).
Independent harmony
- Contrary motion: the voice rises while the melody falls.
- Oblique motion / pedal: one voice holds a note (often the fifth or the tonic) while the melody moves.
- Different rhythm: long notes under a syllabic melody, or responses in the gaps.
- Guide tones: a voice connecting the thirds and sevenths of the chords (see Guide Tone Lines).
- Strengths: richness, depth, more beautiful voice leading; makes the melody stand out by contrast.
- Risks: harder to sing and tune; lyrics less clear if the words don't coincide.
Example over C–Am–F–G
Melody (one note per bar, hypothetical): E4 – C4 – A4 – B4.
- Parallel third above (diatonic): G4 – E4 – C5 – D5.
- Independent with common tones: G4 – A4 – A4 – G4 (stays close, holds the common tone A between Am and F, meets the melody in unison on F and resolves on G below the melody's B4).
The second line is easier to tune (it moves by a whole step at most) and creates contrary motion with the melody.
When to use which
| Situation | Typical choice |
|---|---|
| Sing-along chorus | parallel in thirds, plus octaves |
| Country or folk duet | parallel (third above or below) |
| Vocal pad behind the lead | independent, long notes |
| Emotional bridge | independent, with pedal or contrary motion |
| Gospel choir | parallel blocks in close position, with responses |
| Classical choir | independent, following voice-leading rules |
Mixed techniques
- Parallel in the first half of the phrase, independent toward the cadence (the voices converge on the final note).
- Parallel above the melody and independent below (e.g. third above + pedal on the fifth below).
- Planing: whole chords moving in parallel (Debussy; in pop, backing vocals in parallel triads).
Examples
- The Everly Brothers — All I Have to Do Is Dream (1958): almost constant parallel thirds, the model of close-harmony duets.
- Simon & Garfunkel — The Sound of Silence (1964/1965): parallel harmony in thirds and sixths.
- The Beach Boys — God Only Knows (1966): in the finale several independent vocal lines overlap like a canon.
- Crosby, Stills & Nash — Suite: Judy Blue Eyes (1969): a mix of parallel and independent lines.
Practice exercise
Take an 8-bar melody in C major. Write a parallel diatonic third above and fix the notes that clash with the chords. Then write an independent harmony under the melody that moves by at most a whole step at a time and holds common tones. Record both and compare: use the parallel in the chorus and the independent in the bridge.
Links
Pop Choral Arranging, Countermelody and Obbligato, Voice-Leading Rules, Guide Tone Lines, Barbershop and Close Harmony.