consonant
when the notes of the chord fit within the key (it sounds normal/boring harmony)
dissonant
when the notes of the chord don’t always fit within the key (it sounds clashing)
primary chords
chords 1, 4 and 5 (I, IV and V)
cadence
the 2 chords at the end of a phrase
perfect cadence
chords V - I, sounds finished
imperfect cadence
chords I - V, sounds unfinished
plagal cadence
chords IV - I, sounds like ‘amen’
interrupted cadence
chords I - vi, changes key, sounds unexpected
pedal note
a harmonic device, a note is held or repeated while the chords change above it