4/3
| Interval information |
reduced,
reduced subharmonic
[sound info]
4/3 is the frequency ratio of the just perfect fourth. Its inversion is the perfect fifth, 3/2. In the florid organum of Medieval music, 4/3 was reliably considered a consonance, and indeed was frequently emphasized. Once major thirds with a tuning approximating 5/4 began to be treated as consonances, however, the perception of 4/3 was altered to where it was at times considered a dissonance.