Editing Interval (music) (section)

=== Diatonic and chromatic ===
{{Main|Diatonic and chromatic}}
In general,

* A ''[[diatonic]] interval'' is an interval formed by two notes of a [[diatonic scale]].
* A ''chromatic interval'' is a non-diatonic interval formed by two notes of a [[chromatic scale]].

[[File:Chromatic scale full octave ascending and descending on C.PNG|thumb|500px|Ascending and descending chromatic scale on C[[File:ChromaticScaleUpDown.ogg]]]]

The table [[#Quality|above]] depicts the 56 diatonic intervals formed by the notes of the C major scale (a diatonic scale). Notice that these intervals, as well as any other diatonic interval, can be also formed by the notes of a chromatic scale.

The distinction between diatonic and chromatic intervals is controversial, as it is based on the definition of diatonic scale, which is variable in the literature. For example, the interval B–E{{music|flat}} (a [[diminished fourth]], occurring in the [[Harmonic minor scale|harmonic C-minor scale]]) is considered diatonic if the harmonic minor scales are considered diatonic as well.<ref>See for example William Lovelock, ''The Rudiments of Music'' (New York: St Martin's Press; London: G. Bell, 1957): {{Page needed|date=August 2015}}, reprinted 1966, 1970, and 1976 by G. Bell, 1971 by St Martins Press, 1981, 1984, and 1986 London: Bell & Hyman. {{ISBN|9780713507447}} (pbk). {{ISBN|9781873497203}}</ref> Otherwise, it is considered chromatic. For further details, see the [[Diatonic and chromatic|main article]].

By a commonly used definition of diatonic scale{{efn|name=diatonic}} (which excludes the [[harmonic minor]] and [[melodic minor]] scales), all perfect, major and minor intervals are diatonic. Conversely, no augmented or diminished interval is diatonic, except for the augmented fourth and diminished fifth.

[[File:Ab major scale.png|right|thumb|[[A-flat major|A{{music|b}}-major]] scale[[File:Ab major scale.mid]]]]

The distinction between diatonic and chromatic intervals may be also sensitive to context. The above-mentioned 56 intervals formed by the C-major scale are sometimes called ''diatonic to C major''. All other intervals are called ''chromatic to C major''. For instance, the perfect fifth A{{Music|flat}}–E{{Music|flat}} is chromatic to C major, because A{{Music|flat}} and E{{Music|flat}} are not contained in the C major scale. However, it is diatonic to others, such as the A{{Music|flat}} major scale.