Unison vs. Octave — What's the Difference?

In music, unison is two or more musical parts that sound either the same pitch or pitches separated by intervals of one or more octaves, usually at the same time. Rhythmic unison is another term for homorhythm.

In music, an octave (Latin: octavus: eighth) or perfect octave (sometimes called the diapason) is the interval between one musical pitch and another with double its frequency. The octave relationship is a natural phenomenon that has been referred to as the "basic miracle of music," the use of which is "common in most musical systems." The interval between the first and second harmonics of the harmonic series is an octave.

Identity of pitch; the interval of a perfect prime.

The interval of eight diatonic degrees between two tones of the same name, the higher of which has twice as many vibrations per second as the lower.

The combination of parts at the same pitch or in octaves.

A tone that is eight diatonic degrees above or below another given tone.

The action of speaking the same words simultaneously

Two tones eight diatonic degrees apart that are sounded together.

Performance of an action at the same time

The consonance that results when two tones eight diatonic degrees apart are sounded.

Agreement; concord

A series of tones included within this interval or the keys of an instrument that produce such a series.

Identical pitch between two notes or sounds; the simultaneous playing of notes of identical pitch (or separated by one or more octaves).

An organ stop that produces tones an octave above those usually produced by the keys played.

A sound or note having the same pitch as another, especially when used as the base note for an interval; a unison string.

The interval between any two frequencies having a ratio of 2 to 1.

The state of being in harmony or agreement; harmonious agreement or togetherness, synchronisation.

The eighth day after a feast day, counting the feast day as one.

(by extension) Two or more voices speaking the same words together.

The entire period between a feast day and the eighth day following it.

Harmony; agreement; concord; union.

A group or series of eight.

Identity in pitch; coincidence of sounds proceeding from an equality in the number of vibrations made in a given time by two or more sonorous bodies. Parts played or sung in octaves are also said to be in unison, or in octaves.

A group of eight lines of poetry, especially the first eight lines of a Petrarchan sonnet. Also called octet.

A single, unvaried.

A poem or stanza containing eight lines.

Sounding alone.

(Sports) A rotating parry in fencing.

Sounded alike in pitch; unisonant; unisonous; as, unison passages, in which two or more parts unite in coincident sound.

(music) An interval of twelve semitones spanning eight degrees of the diatonic scale, representing a doubling or halving in pitch frequency.

Corresponding exactly;

(music) The pitch an octave higher than a given pitch.

Occurring together or simultaneously;

(music) A coupler on an organ which allows the organist to sound the note an octave above the note of the key pressed (cf sub-octave)

(music) two or more sounds or tones at the same pitch or in octaves;

(poetry) A poetic stanza consisting of eight lines; usually used as one part of a sonnet.

(fencing) The eighth defensive position, with the sword hand held at waist height, and the tip of the sword out straight at knee level.

(Christianity) The day that is one week after a feast day in the Latin rite of the Catholic Church.

(Christianity) An eight-day period beginning on a feast day in the Latin rite of the Catholic Church.

A small cask of wine, one eighth of a pipe.

An octonion.

(signal processing) Any of a number of coherent-noise functions of differing frequency that are added together to form Perlin noise.

(astrology) The subjective vibration of a planet.

(obsolete) Consisting of eight; eight in number.

The eighth day after a church festival, the festival day being included; also, the week following a church festival.

The eighth tone in the scale; the interval between one and eight of the scale, or any interval of equal length; an interval of five tones and two semitones.

The first two stanzas of a sonnet, consisting of four verses each; a stanza of eight lines.

A small cask of wine, the eighth part of a pipe.

Consisting of eight; eight.

A feast day and the seven days following it

A musical interval of eight tones

A rhythmic group of eight lines of verse