Editing Augmented triad (section)

==Analysis==
Whereas a [[Major chord|major triad]], such as C–E–G, contains a [[major third]] (C–E) and a minor third (E–G), with the interval of the fifth (C–G) being [[Interval quality|perfect]], the augmented triad has an [[augmented fifth]], becoming C–E–G{{music|sharp}}. In other words, the top note is raised a [[semitone]]. H.R. Palmer notes:

{{blockquote|The augmented chord, (which appears upon three of the minor key,) is commonly found upon one, four, or five of a major key. In its resolution the fundamental may either remain stationary, descend five degrees, or ascend four degrees; the third may either ascend a minor second [I+, IV ({{audio|Augmented chord progression I+ IV Palmer.mid|Play}}) and I+, IV{{su|p=6|b=4}} ({{audio|Augmented chord progression I+ IV64 Palmer.mid|Play}})], or remain stationary [I+, vi{{su|p=6|b=3}} ({{audio|Augmented chord progression I+ vi63 Palmer.mid|Play}})]; and the fifth ascends a minor second. The inversions of the augmented chord may also be used [I+{{sup|{{music|sharp}}6}}, IV ({{audio|Augmented chord progression I+sharp6 IV Palmer.mid|Play}}) and I+{{su|p=6|b=4}}, IV{{sup|6}} ({{audio|Augmented chord progression I+64 IV6 Palmer.mid|Play}})].<ref name="Palmer">{{cite book|last=Palmer|first=H. R.|date=1876|url=https://archive.org/details/palmerstheoryofm00palm|quote=augmented chord.|title=Palmer's Theory of Music|pages=[https://archive.org/details/palmerstheoryofm00palm/page/91 91]–92|publisher=J. Church}}{{pre-ISBN}}</ref>|sign=|source=}}

The augmented chord on I may contain the [[Augmented major seventh chord|major seventh]] (I{{su|p=7|b=5}} ({{audio|Augmented chord progression I+75 IV Palmer.mid|Play}}) or I{{su|p=6|b=5}} ({{audio|Augmented chord progression I+65 IV Palmer.mid|Play}})), while the augmented chord on V may contain the [[Augmented seventh chord|minor seventh]] (V{{su|p=7|b=5}} ({{audio|Augmented chord progression V+75 I Palmer.mid|Play}}), V{{su|p=6|b=5}} ({{audio|Augmented chord progression V+65 I Palmer.mid|Play}}), or V{{su|p=4|b=3}} ({{audio|Augmented chord progression V+43 I63 Palmer.mid|Play}})).<ref name="Palmer" /> In C: C–E–G{{music|#}}–B and G–B–D{{music|#}}–F.

The augmented triad on the V may be used as a [[chord substitution|substitute]] [[dominant chord|dominant]], and may also be considered as {{music|b}}III+.<ref>{{cite book|last=Cho|first=Gene|date=1992|title=Theories and Practice of Harmonic Analysis|page=35|isbn=0-7734-9917-2}}</ref> The example below shows {{music|b}}III+ as a substitute dominant in a [[Ii–V–I progression|ii-V-I turnaround]] in C major.<blockquote><score sound="1">
{
\omit Score.TimeSignature
\relative c' {<d f a c>2 <es g b> <c e g c>1 \bar "||" } }
</score></blockquote>
See, for example, Henry [[Purcell]]'s ''[[Dido & Aeneas]]''.[[File:Purcell from Dido & Aeneas, Act 2, scene 1, echo chorus 01.wav|thumb|Purcell from Dido & Aeneas, Act 2, scene 1, echo chorus]][[File:Purcell from Dido & Aeneas, Act 2, scene 1, echo chorus.png|thumb|center|500px|Purcell from Dido & Aeneas, Act 2, scene 1, echo chorus]]