Editing Music theory (section)

===Consonance and dissonance===
{{Main|Consonance and dissonance}}
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| image1 = Perfect octave on C.png
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| caption1 = [[Perfect octave]], a consonant interval[[File:Perfect octave on C.mid]]
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| alt2 = A dissonance
| caption2 = [[Minor second]], a dissonant interval[[File:Minor second on C.mid]]
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[[Consonance and dissonance]] are subjective qualities of the sonority of intervals that vary widely in different cultures and over the ages. Consonance (or concord) is the quality of an interval or chord that seems stable and complete in itself. Dissonance (or discord) is the opposite in that it feels incomplete and "wants to" resolve to a consonant interval. Dissonant intervals seem to clash. Consonant intervals seem to sound comfortable together. Commonly, perfect fourths, fifths, and octaves and all major and minor thirds and sixths are considered consonant. All others are dissonant to a greater or lesser degree.{{sfn|Latham|2002|loc={{Page needed|date=August 2014}}}}

Context and many other aspects can affect apparent dissonance and consonance. For example, in a Debussy prelude, a major second may sound stable and consonant, while the same interval may sound dissonant in a Bach fugue. In the [[Common practice period|Common practice era]], the perfect fourth is considered dissonant when not supported by a lower third or fifth. Since the early 20th century, [[Arnold Schoenberg]]'s concept of "emancipated" dissonance, in which traditionally dissonant intervals can be treated as "higher," more remote consonances, has become more widely accepted.{{sfn|Latham|2002|loc={{Page needed|date=August 2014}}<!--Better would be the title of the article in this dictionary, added to the entry in the list of references, in which case a page number would be superfluous.-->}}