- Augmented triad
Infobox Chord| chord_name=Augmented triad
first_interval=root
second_interval=major third
third_interval=augmented fifth In music, an augmented triad (Audio|Augmented triad on C.mid|play) is a triad consisting of two
major third s.Harmonic considerations
Whereas a
major triad , such as C-E-G, contains amajor third (C-E) then a minor third (E-G), with the interval of the fifth (C-G) being "perfect", the augmented triad sharpens that fifth (to anaugmented fifth ), becoming C-E-G#.If an octave from the root is added, the resulting chord (C-E-G#-C) contains also a diminished fourth (G#-C); this is the
enharmonic equivalent of a major third, so the full-octave chord is, in effect, three major thirds.In
just intonation , the interval between two major thirds and an octave, 2/(5/4)2, is 32/25, which is flatter by aseptimal kleisma of size 225/224 than theseptimal major third with ratio 9/7. Whileseptimal meantone temperament tempers out the septimal kleisma, some other temperaments, for examplemiracle temperament , do so also, and in all of these temperaments the augmented triad may be identified with a circle of two major and one septimal major thirds, making up an octave.In tonal music
The augmented triad differs from the other kinds of triad (the
major triad , theminor triad , and thediminished triad ) in that it does not naturally arise in adiatonic scale . Although it could be conceptualized as a triad built on the third degree of aharmonic minor scale ormelodic minor scale , it virtually never occurs in this way (since any chord on the third degree is itself rare, usually being a new tonic).This makes the augmented triad a special chord that touches on the
atonal . Its uses to 'suspend' tonality are famous; for example, inLiszt 's "Faust Symphony " and inWagner 's "Siegfried Idyll ". However, the augmented triad occurs in tonal music, with a perfectly tonal meaning, since at least Beethoven. It results diatonically in minor mode from adominant chord where the fifth (the second degree) is replaced by the third degree, as an anticipation of the resolution chord.Beethoven 's 9th symphony features such a chord at key moments in the slow movement.Brahms 's "Tragic Overture " also features the chord prominently (A-C#-F), in alternation with the regular dominant (A-C#-E). In this example one can also see other aspect of the appeal of the chord to composers: it is a 'conflation' of the fifth degree and the third degree, the usual contrasting keys of a piece in the minor mode.With the lead of
Schubert (in his "Wanderer Fantasy "), Romantic composers started organizing many pieces by descending major thirds, which can be seen as a large-scale application of the augmented triad (although it probably arose from other lines of development not necessarily connected to the augmented triad). This kind of organization is common; in addition to Schubert, it is found in music of Liszt,Rimsky-Korsakov ,Louis Vierne and Wagner, among others.See also
*
Augmented chord
*Diminished chord
Wikimedia Foundation. 2010.