LEMM: This is harmony. It’s the sound created when two or more notes are played at the same time. BOY 2: What id we add a third note? GIRL 2: We should totally use harmony in our song!

All the chords built on other notes in the scale of C are minor, except chord VII - the notes B – D – F, which is diminished. When a seventh is added to a chord this is known as a seventh chord.