Triad Chords
Senior 3 · Music
Triad Chords
Lesson 1 of 4
25 min
Put your thumb on C, your middle finger on E and your little finger on G, and press all three keys of a keyboard at the same time. You hear one full, settled sound. Now press C, D and E together. The sound is crowded and muddy, because the three notes sit right next to each other. The first group is a triad, the chord that most hymns, choir songs and popular songs are built on.
In S2 (Melody and Harmony) you met the triads of a major scale. In this unit you learn to build a triad on any note, to name its type exactly, to find every triad that belongs to a key, and to use the three most important ones to accompany a song.
Definition
Chord: two or more notes sounded at the same time. Example: C, E and G played together.
Triad: a chord of three notes built by stacking two thirds, one on top of the other. Example: C–E–G (C to E is a third, E to G is a third).
Root: the note a triad is built on and named after. In C–E–G the root is C.
Third and fifth: the notes a third and a fifth above the root. In C–E–G, E is the third and G is the fifth.
Music uses seven letter names, A B C D E F G, and then starts again. To build a triad, write the root, skip a letter, take the next one, skip a letter, take the next one. Counting the root as 1, the third is letter 3 and the fifth is letter 5, which is how the notes get their names.
| Root | Third | Fifth | Triad (letters) |
|---|---|---|---|
| C | E | G | C–E–G |
| D | F | A | D–F–A |
| E | G | B | E–G–B |
| F | A | C | F–A–C |
| G | B | D | G–B–D |
| A | C | E | A–C–E |
| B | D | F | B–D–F |
Because the letters skip one each time, a triad in its basic position looks like a little snowman: three notes stacked on three lines or in three spaces, touching each other. If one note is on a line and its neighbour is in the next space, you have written a step, not a third.
A sharp or flat never changes the letters. D–F–A and D–F♯–A are both triads on D; the accidental changes the type of triad, which is the subject of the next lesson.
Worked example 1: build the triad on A and write it on the treble staff
Worked example
Worked example 2: find the root. A choir sings the notes B (lowest), D and G (highest). Which triad is it, and which note is the root?
A triad does not have to be played on one instrument. Three singers can share it: one sings the root, one the third and one the fifth. In tonic sol-fa, the triad on doh is d–m–s (doh, me, soh), the triad on fah is f–l–d' and the triad on soh is s–t–r'. You will meet these three again in lesson 4, because they are the primary chords.
Class activity. In groups of three, choose a doh that suits your voices. Singer 1 holds d, then singer 2 joins on m, then singer 3 joins on s. Hold the chord for four slow beats and listen for the moment the three notes blend. Swap parts and repeat on f–l–d'.
Video: "Understanding chords", MusicTheoryAcademy. A short lesson on what chords are and how to work them out. Watch how each chord is found from its root by taking every other note, then pause and build the next one yourself before the presenter does.
Tip
Snowman check. After writing a triad, look at its shape: three notes on lines, or three in spaces, touching like a snowman. A gap between two notes, or a note squeezed beside another, means a letter was skipped twice or not at all.
Warning
Common mistake: naming a triad after its lowest note. The root is the note from which the other two are every other letter, wherever it sits. B–D–G (bottom to top) is the G triad, not a B triad.
Practice
Remember
Sources and credits
