Harmony is a dance between overtones. Multiply every frequency by three and you will find yourself with a harmony one octave and a fifth above it. (An octave lower represents a fifth and that ratio is 3/2). If you’ve spent any time looking at an equalizer, mixing drums, or diving into a rich chord, you have been dancing within the harmonic structure of music.

It doesn’t matter if your music is simple or complex. This isn’t just music theory and harmony. It’s acoustics, physics. Every time you play a chord imagine another one a fifth above it and ask yourself what that means in relation to the harmony, the scale, and the chromatic movement of your music.