In music, just intonation (sometimes abbreviated as JI) or pure intonation is any musical tuning in which the frequencies of notes are related by ratios of small whole numbers. Any interval tuned in this way is called a pure or just interval. Pure intervals are important in music because they correspond to the vibrational patterns found in physical objects which correlate to human perception (see harmonic series). The two notes in any just interval are members of the same harmonic series. Frequency ratios involving large integers such as 1024:729 are not generally said to be justly tuned. Wikipedia, Just Intonation
See Also
chord
Figure 14.01 - Overtones Developed Musically Showing Up as Isotopes along the Vertical Axis of this Chart
Harmonic
Interval
Intonation
Overtone
overtone position
Overtone series
Perfect Intonation
Scale
Scale of Mathematical Intonation
Undertone
9.9 - Sympathy or Harmony Between Harmonics or Overtones