Intervals

Two sounds, one ratio. The simpler the ratio, the more order appears both to the ear and in the figure; listen to just and equal-tempered intervals side by side.

Ratio

Perfect fifth · 220 Hz · 330 Hz

At an exact ratio the figure closes and stands still.

Ratio
3:2
Just
701.96 cents
Equal
700 cents
Difference
−1.96 cents
Complexity: log₂(6) = 2.58
1234567812345678
Top: harmonics of the lower sound; bottom: of the upper sound. Solid line: coinciding harmonics (2); dashed line: rough near-misses (0).

Settings

Timbre
Tuning
Playing

1859

Lissajous figures were used to compare tuning forks for the 1859 French pitch standard: when light was reflected off two forks together, the figure stood still at an exact ratio and turned if the pitch was off.

A history of tuning: from 415 to 443Intervals and ratios: why does 3:2 sound consonant?