1/1

Interval information

Ratio

1/1

Factorization

n/a

Monzo

[0⟩

Size in cents

0¢

Names

unison,
perfect unison,
prime,
perfect prime,
1st harmonic

FJS name

[math]\displaystyle{ \text{P1} }[/math]

Special properties

reduced,
harmonic,
highly composite harmonic

Tenney height (log₂ nd)

0

Weil height (log₂ max(n, d))

0

Wilson height (sopfr(nd))

0

Open this interval in xen-calc

The unison (interval ratio 1/1) is the interval between two tones that are identical in pitch. In the harmonic series, 1/1 is the 1st harmonic.

English Wikipedia has an article on:

Unison

Measured in cents (or any other logarithmic measure such as millioctaves, EDO steps, etc.), the unison's size is exactly 0. This is because the distance between two identical pitches is zero. As such, the unison can be considered as a degenerate interval.

In just intonation, 1/1 represents the base frequency from which an interval is measured.

1/1

See also