Harmony Essentials

Here is what you need to understand about harmony:

• Chords are built by stacking notes in intervals of thirds (major or minor)
• Consonance feels stable (simple frequency ratios); dissonance feels tense (complex ratios)
• Chord progressions create emotional narratives by moving between stability and tension
• Key is the home base; modulating to a new key creates surprise and emotional shift
• Harmonic complexity varies by genre: pop uses three or four chords, jazz uses dozens with extensions, classical modulates through multiple keys

Harmony is what separates a campfire singalong from a symphony orchestra.