Editing Scale (music) (section)

==Background==

===Scales, steps, and intervals===
[[File:C chromatic circle.svg|thumb|Diatonic scale in the [[chromatic circle]]]]
Scales are typically listed from low to high pitch. Most scales are ''[[octave]]-repeating'', meaning their pattern of notes is the same in every octave (the [[Bohlen–Pierce scale]] is one exception). An octave-repeating scale can be represented as a circular arrangement of pitch classes, ordered by increasing (or decreasing) pitch class. For instance, the increasing C major scale is C–D–E–F–G–A–B–[C], with the bracket indicating that the last note is an octave higher than the first note, and the decreasing C major scale is C–B–A–G–F–E–D–[C], with the bracket indicating an octave lower than the first note in the scale.

The distance between two successive notes in a scale is called a [[Degree (music)|scale step]].

The notes of a scale are numbered by their steps from the first degree of the scale. For example, in a C major scale the first note is C, the second D, the third E and so on. Two notes can also be numbered in relation to each other: C and E create an interval of a third (in this case a major third); D and F also create a third (in this case a minor third).

===Pitch===
A single scale can be manifested at many different pitch levels. For example, a C major scale can be started at C4 (middle C; see [[scientific pitch notation]]) and ascending an octave to C5; or it could be started at C6, ascending an octave to C7.

===Types of scale===
{{Image frame|content=<score sound="1"> {
\override Score.TimeSignature #'stencil = ##f
\relative c' {
  \clef treble \time 12/4
  c4 cis d dis e f fis g gis a ais b
  c2
  }
}
</score>|width=350|caption=The [[chromatic scale]], ascending}}Scales may be described according to the number of different pitch classes they contain:

* [[chromatic scale|Chromatic]], or dodecatonic (12 notes per octave)
*[[Blues scale#Nonatonic|Nonatonic]] (9 notes per octave): a [[Chromatic scale|chromatic]] variation of the [[Blues scale#Heptatonic|heptatonic blues scale]]
* [[octatonic scale|Octatonic]] (8 notes per octave): used in [[jazz]] and [[modernism (music)|modern classical music]]
* [[heptatonic scale|Heptatonic]] (7 notes per octave): the most common modern Western scale
* [[hexatonic scale|Hexatonic]] (6 notes per octave): common in Western folk music
* [[pentatonic scale|Pentatonic]] (5 notes per octave): the anhemitonic form (lacking semitones) is common in folk music, especially in Asian music; also known as the "black note" scale
* [[tetratonic scale|Tetratonic]] (4 notes), [[tritonic scale|tritonic]] (3 notes), and [[ditonic scale|ditonic]] (2 notes): generally limited to [[prehistoric music|prehistoric]] ("primitive") music
Scales may also be described by their constituent intervals, such as being [[hemitonia|hemitonic]], [[cohemitonia|cohemitonic]], or having imperfections.<ref>{{cite web|url=http://www.allthescales.org/intro.html#Perfection|title=All The Scales|website=www.allthescales.org|access-date=28 April 2018|url-status=live|archive-url=https://web.archive.org/web/20171015071228/http://allthescales.org/intro.html#Perfection|archive-date=15 October 2017}}</ref> Many music theorists concur that the constituent intervals of a scale have a large role in the cognitive perception of its sonority, or tonal character.

"The number of the notes that make up a scale as well as the quality of the intervals between successive notes of the scale help to give the music of a culture area its peculiar sound quality."<ref>Nzewi, Meki, and Odyke Nzewi (2007), ''A Contemporary Study of Musical Arts''. Pretoria: Centre for Indigenous Instrumental African Music and Dance. Volume 1 p. 34 {{ISBN|978-1-920051-62-4}}.</ref> "The pitch distances or intervals among the notes of a scale tell us more about the sound of the music than does the mere number of tones."<ref>Nettl, Bruno, and Helen Myers (1976). ''Folk Music in the United States'', p.39. {{ISBN|978-0-8143-1557-6}}.</ref>

Scales may also be described by their symmetry, such as being [[palindrome|palindromic]], [[Chirality|chiral]], or having rotational symmetry as in Messiaen's [[modes of limited transposition]].

===Harmonic content===
The notes of a scale form intervals with each of the other notes of the chord in [[combination]].  A 5-note scale has 10 of these [[Harmony|harmonic]] intervals, a 6-note scale has 15, a 7-note scale has 21, an 8-note scale has 28.<ref name=":0">Hanson, Howard. (1960) ''Harmonic Materials of Modern Music'', pp.7ff. New York: Appleton-Century-Crofts. LOC 58-8138.</ref> Though the scale is not a [[Chord (music)|chord]], and might never be heard more than one note at a time, still the absence, presence, and placement of certain [[key (music)|key]] intervals plays a large part in the sound of the scale, the natural movement of melody within the scale, and the selection of [[Chord (music)|chords]] taken naturally from the scale.<ref name=":0" />

A musical scale that contains [[tritone]]s is called tritonic (though the expression is also used for any scale with just three notes per octave, whether or not it includes a tritone), and one without tritones is ''atritonic''.  A scale or [[Chord (music)|chord]] that contains semitones is called hemitonic, and without semitones is [[Anhemitonic scale|anhemitonic]].

===Scales in composition===
Scales can be abstracted from [[performance]] or [[musical composition|composition]]. They are also often used [[precompositional]]ly to guide or limit a composition. Explicit instruction in scales has been part of compositional training for many centuries. One or more scales may be used in a composition, such as in [[Claude Debussy]]'s ''[[L'Isle Joyeuse]]''.<ref>{{cite journal
 |last        = Tymoczko
 |first       = Dmitri
 |author-link = Dmitri Tymoczko
 |year        = 2004
 |title       = Scale Networks and Debussy
 |url         = http://dmitri.mycpanel.princeton.edu/files/publications/debussy.pdf
 |journal     = Journal of Music Theory
 |volume      = 48
 |issue       = 2
 |pages       = 219–294 (254–264)
 |issn        = 0022-2909
 |doi         = 10.1215/00222909-48-2-219
 |access-date = 18 July 2017
 |url-status     = live
 |archive-url  = https://web.archive.org/web/20170809095900/http://dmitri.mycpanel.princeton.edu/files/publications/debussy.pdf
 |archive-date = 9 August 2017
}}.</ref> To the right, the first scale is a whole-tone scale, while the second and third scales are diatonic scales. All three are used in the opening pages of Debussy's piece.