Name the triad

Three keys light up; the orange one is the root. You know how to build these chords — now read one back from its shape.

Look at the bottom third, root to middle note. Four semitones means major; three means minor. The top completes to seven either way.

Each root has its own visual shape — D major looks nothing like D♭ major on the keys — which is why every root is practised.

bottom third: 4 semitones = major · 3 = minor

C to E is four semitones: C major.

Practise this in the trainer — it opens with this lesson the first time the concept comes up.