Equivalence

This page is about the psychoacoustic phenomenon of different pitches sounding similar. For using multiple names for the same pitch in notation, see enharmonic equivalence.

English Wikipedia has an article on:

Octave #Equivalence

Equivalence is the phenomenon of psychoacoustics that two notes an octave apart are considered substantially similar to the brain. The question of whether it can (and should) generalize or generalizes to other intervals is still being studied. This question relates to the height of the interval's denominator in the (odd) harmonic series and another phenomenon presumably of psycho-acoustics that melodies within the range of a tenth are considered to sound "cohesive" or "coherent" to the brain. If equivalence can be perceived for other intervals, the best candidates are those of very high consonance, such as 3/1, the next harmonic after the octave.

The set of all equivalent pitches is a pitch class.

See also

• Equave