- Chord = two or more tones written or played simultaneously
- Triads = most basic chords made up of specific arrangements of 3 notes
- Triad = root + third + fifth
- Major triad = root + major third + perfect fifth
- Minor triad = root + minor third + perfect fifth
- Augmented triad = root + major third + augmented fifth
- Diminished triad = root + minor third + diminished fifth
- Major triad vs minor triad: both consonant (having a sound that is generally described as smooth, stable, restful) but have different triad quality (major third and minor third)
- Augmented triad & diminished triad => dissonant sound
