Editing Unison

{{Short description|Musical parts sounding at the same pitch}}
{{other uses}}
[[File:Unison on C.png|thumb|Perfect unison {{audio|Unison on C.mid|Play}}]]
In [[music]], '''unison''' is two or more [[part (music)|musical parts]] that sound either the same [[pitch (music)|pitch]] or pitches separated by [[interval (music)|interval]]s of one or more [[octave]]s, usually at the same time. '''''Rhythmic unison''''' is another term for [[homorhythm]].<ref name=grove>{{cite web|last=Rushton|first=Julian|author-link=Julian Rushton|title=Unison [prime]|url=http://www.oxfordmusiconline.com/subscriber/article/grove/music/28790|work=[[Grove Music Online]]|publisher=Oxford University Press|url-access=subscription|access-date=May 4, 2020}}</ref>

==Definition==
{{anchor|Divisi|Unison (orchestra)}}<!-- This section is the target of Redirect: Divisi (music) and other links-->
{{Infobox Interval
|       main_interval_name = unison
|       inverse = [[octave]]
|       complement = unison
|       other_names = perfect unison, prime, perfect prime
|       abbreviation = P1
|       semitones = 0
|       interval_class = 0
|       just_interval = 1:1
|       cents_equal_temperament = 0
|       cents_24T_equal_temperament = 
|       cents_just_intonation = 0
}}
{{quote|Two pitches that are the same or two that move as one.<ref name="B&S">Benward, Bruce, and Marilyn Nadine Saker (2003). ''Music: In Theory and Practice'', Vol. I, seventh edition, p. 364. Boston: McGraw-Hill. {{ISBN|978-0-07-294262-0}}.</ref>}}
'''Unison''' or '''perfect unison''' (also called a '''prime''', or '''perfect prime''')<ref>Benward & Saker (2003), p. 53.</ref> may refer to the (pseudo-) [[Interval (music)|interval]] formed by a tone and its duplication (in German, ''Unisono'', ''Einklang'', or ''Prime''), for example C–C, as differentiated from the [[Major second|second]], C–D, etc. In the unison the two pitches have the ratio of 1:1 or 0 [[Minor second|half step]]s and zero [[cent (music)|cents]]. Although two tones in unison are considered to be the same pitch, they are still perceivable as coming from separate sources, whether played on instruments of a different type: {{audio|Unison piano guitar C.mid|play unison on C, piano and guitar}}; or of the same type: {{audio|Unison piano C.mid|play unison on C, two pianos}}. This is because a pair of tones in unison come from different locations or can have different "colors" ([[timbre]]s), i.e. come from different [[musical instrument]]s or human voices.  Voices with different colors have, as sound waves, different [[waveform]]s.  These waveforms have the same fundamental [[frequency]] but differ in the amplitudes of their higher [[harmonic]]s. The unison is considered the most [[Consonance and dissonance#Consonance|consonant]] interval while the [[minor second|near unison]] is considered the most [[Consonance and dissonance#Dissonance|dissonant]]. The unison is also the easiest interval to [[Musical tuning|tune]]. The unison is abbreviated as "P1".

However, the unison was questioned by [[Gioseffo Zarlino|Zarlino]] as an interval for lacking contrast and compared to a [[point (geometry)|point]] in geometry:{{quote|Equality is never found in consonances or intervals, and the unison is to the musician what the point is to the geometer. A point is the beginning of a [[line (geometry)|line]], although, it is not itself a line. But a line is not composed of points, since a point has no length, width, or depth that can be extended, or joined to another point. So a unison is only the beginning of consonance or interval; it is neither consonance nor interval, for like the point it is incapable of extension.<ref>Thomas Street Christensen (2004). ''Rameau and Musical Thought in the Enlightenment'', p. 76. {{ISBN|978-0-521-61709-3}}.</ref>}}

==Performance ensembles==
{{Anchor|"In unison"}}<!--[[Divisi]] redirects directly here-->
{{Refimprove section|date=August 2011}}
[[File:Twinkle Twinkle in unison.png|thumb|upright=1.5|"[[Twinkle, Twinkle, Little Star]]" melody doubled in unison. {{Audio|Twinkle Twinkle in unison.mid|Play}} clarinet & [[pizzicato|pizz.]] violin]]
[[File:Twinkle Twinkle in octaves.png|thumb|upright=1.5|"Twinkle, Twinkle, Little Star" melody doubled in four octaves. {{Audio|Twinkle Twinkle in octaves.mid|Play}} piano]]
{{quote|Several singers singing a melody together.<ref name="B&S"/>}}
In orchestral music ''unison'' can mean the simultaneous playing of a note (or a series of notes constituting a [[melody]]) by different instruments, either at the same [[Pitch (music)|pitch]]; or in a different [[octave]], for example, [[cello]] and [[double bass]] (''all'unisono''). Typically a section string player plays unison with the rest of the section. Occasionally the Italian word ''[[divisi]]'' (meaning ''divided'', abbrev. ''div.'') marks a point where an instrumental section, typically the first violins, is to be divided into two groups for rendering passages that might, for example, include full [[Chord (music)|chords]].  Thus, in the ''divisi'' first violins the "outside" players (nearer the audience) might play the top note of the chord, while the "inside" seated players play the middle note, and the second violins play the bottom note. At the point where the first violins no longer play ''divisi'', the score may indicate this with ''unison'' (abbrev. ''unis.'').

When an entire [[choir]] sings the main melody, the choir usually sings in unison. Music in which all the notes sung are in unison is called [[monophony|monophonic]]. In a choir with two or more sections, such as for different [[vocal range]]s, each section typically sings in unison. Part singing is when two or more voices sing different notes. [[Homophony]] is when choir members sing different pitches but with the same rhythm. [[Polyphony]] is when the chorus sings multiple independent melodies.

==Synthesizer==
On [[synthesizer]]s, the term ''unison'' is used to describe two or more [[oscillator]]s generating the same pitch/notes as each other, which can result in a fatter or thicker sound (especially if tiny changes are made to each oscillator's tuning). 

However, if each oscillator is tuned so far from the other oscillators that they aren't generating the same note then technically they aren't in unison. 

If they are playing the same note but in a different octave then they are still in unison. For example, a melody consisting of A-B-C-B-A-A-A if played in a different octave is still A-B-C-B-A-A-A therefore this is still considered as ''in unison''.

Unison refers to ''everything doing the same thing''.

==See also==
* [[Interval (music)|List of musical intervals]]
* [[List of pitch intervals]]

==References==
{{reflist}}

==Further reading==
* [[Willi Apel|Apel, Willi]], ed., ''Harvard Dictionary of Music'', Second Edition, Revised and Enlarged. The Belknap Press of Harvard University Press, Cambridge, Massachusetts, 1969. {{ISBN|0-674-37501-7}}.

{{Intervals}}

[[Category:Unisons| ]]
[[Category:Just tuning and intervals]]
[[Category:Perfect intervals]]
[[Category:3-limit tuning and intervals]]