In our modern world, we use a different system called "Equal Temperament" (ET), which is a compromise. Just Intonation is the "Natural State" we abandoned for the sake of convenience.
In Just Intonation, the notes are derived directly from the Harmonic Series. When two notes vibrate in a simple ratio, their wave patterns overlap perfectly, creating a "locked" sound with zero interference.The Octave ($2:1$): The most stable ratio.The Perfect Fifth ($3:2$): The backbone of the Divine Monochord.The Difference: In Equal Temperament, the octave is divided into 12 exactly equal parts. To make this work, the ratios are slightly "out of tune" with physics. For example, a "perfect fifth" in ET is slightly flat compared to the pure $3:2$ ratio of Just Intonation.
Researcher Note:
Cacophony by Design: Beating occurs when two frequencies are so close that they periodically cancel each other out. In Just Intonation, there is no beating; the chord sounds "still," like a Standing Wave. It feels grounded and ancient.
Cacophony by Design: Beating occurs when two frequencies are so close that they periodically cancel each other out. In Just Intonation, there is no beating; the chord sounds "still," like a Standing Wave. It feels grounded and ancient.