Harmonising Melodies

In this lesson, we will learn how to transform a melody into a variety of chord accompaniments. This is a common technique, especially among music players who work with choirs. For example, if someone creates a melody that includes the i, iii, iv, vi, vii, and viii notes of a scale (as shown below), then harmonising this melody means playing a chord accompaniment for each note of the melody.

Harmonising a Major Melody
In a major key, harmonising a melody means creating a chord accompaniment for it. Since the I, IV, and V (or V7) chords include all the notes of the major scale, many melodies in major keys can be harmonized using just these three chords.
To determine which chords to use, you need to analyze the notes of the melody. Refer to the following chart to see which chords are commonly used with the melody notes of each major scale. When there are multiple chords to choose from, your hearing should always be the ultimate guide.

Harmonising Major Melodies

In a major key, melodies can often be harmonised using I, IV, and V (or V7) chords, as these contain all notes of the major scale. Use the chart below to match scale degrees with chords. When multiple options exist, let your ears decide:

Examples in C Major

Using I, IV, and V Chords

Melody: C → D → E → F → G → A → B → C  
Chords: 
I (C) → V (G) → I (C) → IV (F) → V (G) → IV (F) → V (G) → I (C)  
 

Using I, ii, IV, and V Chords

Melody: C → D → E → F → G → A → B → C  
Chords:  
I (C) → ii (Dm) → IV (F) → V (G) → I (C) → IV (F) → V (G) → I (C)  

Pro Tip: Use inversions to place the melody note as the highest chord tone.

Non-Chord Tones: Passing Tones & Neighbour Tones

• Passing Tones: Non-chord notes that connect two chord tones (e.g., moving from C to E via D).
• Neighbour Tones: Non-chord notes that return to the original chord tone (e.g., C → D → C).
  • Upper Neighbour: A step above the chord tone.
  • Lower Neighbour: A step below the chord tone.

Example (Mary Had a Little Lamb):

Melody: E-D-C-D-E-E-E (C Major)  
Analysis:  
- E (I chord) → D (passing tone) → C (I chord) → D (neighbor tone) → E (I chord)  
- Repeated Es highlight the I chord (C Major).  

Steps to Harmonize a Melody

1. Analyse the Melody:
   • Identify the key and scale degrees.
   • Mark chord tones (aligned with I, IV, V, or ii).
   • Label non-chord tones (passing/neighbour tones).
2. Assign Chords:
   • Prioritise chords where multiple melody notes align (e.g., repeated notes).
   • Use inversions to keep the melody note as the highest tone.
   • Resolve to V → I at cadences for closure.

Advanced Tips

• IV Chord Substitution: The IV chord in root position (e.g., F Major in C) can harmonize the tonic (C) when inverted (F/A).
• Dominant 7th Flexibility: V7 chords can harmonize degrees 2, 4, 5, 7 (e.g., G7 for F in C Major).
• Rhythmic Alignment: Sync chord changes with strong beats, leaving non-chord tones on weak beats.

Example Harmonisation (C Major Scale)

Melody: C → D → E → F → G → A → B → C  
Chords (Inversions):  
C/E → Dm/F → C/G → F/A → G/B → C/E → G/D → C  

Explanation:

• Each inversion places the melody note on top.
• Non-chord tones (e.g., D, A) are treated as passing/neighbour tones.

Here are some tips for distinguishing chord notes in a melody:

If a chord is arpeggiated, it can be used to harmonize the melody
For example, if I created a melody like this: C-E-G-A-C. Notice that I am actually playing the C major chord in sequence (playing the notes of the chord separately). Therefore, my other notes will be transition notes or neighbor notes, depending on their function. In this example, the "A" note is considered a transition note because it is used to transition from one chord note (from G to C) to another chord note. I will play this melody on the Cmaj chord.

If a note is repeated multiple times in a measure, it is most likely a chord note
Notice in measure 2 of "Mary had a Little Lamb" that the "E" note is repeated three times in one measure. "E" is the chord note of Cmaj. Therefore, this measure should be played on the Cmaj chord. A similar situation occurs in measure 3, with three "0" notes. Since D is the chord note of Gmaj, this measure should be played on the Gmaj chord.

If two different chord notes of the same chord appear in one measure, the chord is most likely an accompaniment chord.
This is demonstrated in measure 1 of "Mary had a Little Lamb". The melody is "E-0-C-D". Since E and C are the chord notes of Cmaj, this measure should be played on the Cmaj chord. But notice that there are two "0" notes, and the previous rule says "If a note is repeated multiple times in a measure, it is most likely a chord note". While this is still true, if two different notes of the same chord appear in one measure, this rule is more important because the chord has a greater chance of being an accompaniment (because 2 of the 3 notes are being used for the melody, not just 1). Therefore, the "D" note becomes a transition note because it is used to transition from one chord note (from E to C) back to the same chord note.
Remember that most songs end with a V chord resolving to an I chord
This is demonstrated in measure 7 of "Mary had a Little Lamb". When the song ends, if there are notes from the V chord before the end, those notes are likely related to the V7 chord, which will eventually resolve to the main chord (I chord). Notice that there are 3 "D" notes. Since it is played three times in one measure and is the chord note of the Gmaj (or G7) chord, it is likely played on the Gmaj or G7 chord. Therefore, the "E" note becomes a neighbour note because it is used to go from one chord note back to the same chord note.