Melody and Harmony
Senior 2 · Music
Melody and Harmony
Lesson 5 of 5
25 min
Your class is preparing a song for a school event, and someone has a guitar or a keyboard. Can you make the chords to go with the tune? If you know the primary triads, the answer is yes. Harmonising a melody means choosing chords to go under it. In this lesson you learn how to play I, IV and V on two common instruments, and a step-by-step method for choosing the right chord under each part of a tune.
On a keyboard, the right hand usually plays the melody and the left hand plays the chords. A triad is played with fingers 5, 3 and 1 of the left hand (little finger, middle finger, thumb) on every other white key. In C major:
| Chord | Left-hand notes | Shape |
|---|---|---|
| I (C) | C E G | three white keys, skipping one between each |
| IV (F) | F A C | the same shape, moved up to F |
| V (G) | G B D | the same shape, moved up to G |
You can play a chord as a block chord (all notes together) or as a broken chord (the notes one after another, for example C, G, E, G). Broken chords make a gentle, flowing accompaniment.
On the guitar, the easiest major key for beginners is G major, because its three primary chords can all be played with open strings. A chord diagram shows the strings as vertical lines (thickest string on the left) and the frets as horizontal lines. A dot shows where a finger presses; o means play the string open; × means do not play it.
Check the G chord: the strings sound G, B, D, G, B, G, which are only the notes of the G major triad. You can strum each chord once per beat, or pick the strings one at a time to make broken chords.
This traditional tune is out of copyright. It was first printed in France in 1761 as Ah! vous dirai-je, maman, and the English words are by Jane Taylor (1806). In C major, the chords are C (I), F (IV) and G (V). We change chord every two beats.
| Bar | Melody notes (sol-fa) | Chord for beats 1–2 | Chord for beats 3–4 |
|---|---|---|---|
| 1 | C C G G (d d s s) | C is in C E G: I | G is in C E G: I |
| 2 | A A G (l l s) | A is in F A C: IV | G is in C E G: I |
| 3 | F F E E (f f m m) | F is in F A C: IV | E is in C E G: I |
| 4 | D D C (r r d) | D is in G B D: V | C is in C E G: I |
The last two chords are V then I, a perfect cadence, so the phrase ends with a full stop. The left hand keeps each chord close to the one before, so the hand hardly moves.
Frère Jacques, another traditional tune, begins C D E C (d r m d). With one chord for the whole bar, choose I: C and E are in C E G, and D is a passing note between them on a weak beat.
Tip
Strong beats, chord notes, V to I. Find the melody note on each strong beat, pick the primary chord that contains it, let weak-beat notes pass by step, and finish with V then I. If two chords both contain the note (G is in both I and V in C major), choose the one that sounds smoother after the chord before it.
In C major, a phrase ends with the melody E D C (m r d), one note per half-bar. Choose a primary chord for each note.
Solution: E is in C E G, so I; D is in G B D, so V; C is in C E G, so I. The ending V to I is a perfect cadence.
In G major, which primary chord would you use under a long melody note F♯?
Solution: the primary chords of G major are G B D, C E G and D F♯ A. Only D major (V) contains F♯.
Mugisha harmonises the final note C of a melody in C major with a G major chord. What goes wrong, and how should he fix it?
Solution: C is not in G B D, so the last note clashes with the chord, and the song ends on V, which sounds unfinished. He should use chord I (C E G), which contains C, so that the phrase ends V to I.
Which three chords would a guitarist use to play I, IV and V in G major, and which of them uses all six strings?
Solution: G, C and D. Only G uses all six strings; C leaves out the low E string and D leaves out the two lowest strings.
Remember
Sources and credits
The bass clef, the harmonisation, the chord diagrams, the notation drawings and the practice were written by Ganzaa.
This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.
