Diatonic triads
Many types of music use only diatonic triads, which are the seven chords built on each of the notes in the chosen major or minor scale.
Create a triad built on each note in the C major scale. To do this, add additional notes a third and a fifth above each note in the scale:
This is all seven diatonic triads in C major (plus another C major triad an octave higher).
Now try it with the C minor scale:
This is all seven diatonic triads in C minor (plus another C minor triad an octave higher).
Now that you've explored the diatonic triads in the keys of C major and C minor, let's look at how they work in other keys.