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The chord of the sixth, so called because its principal interval is the sixth, has also its three positions, like the perfect common chord. Example:
![\new PianoStaff << \new Staff \relative { \time 4/4 \override Score.TimeSignature #'stencil = ##f <c' g' c>1 \bar ".." <g' c e> \bar ".." <g c g'> \bar ".." } \new Staff { \clef bass e^\markup { \teeny { Sixth position. } } e^\markup { \teeny { Octave position. } } e^\markup { \teeny { Third position. } } } >>](http://upload.wikimedia.org/score/p/9/p97g3ectika0byu5z7m37m6hbfkdjal/p97g3ect.png)
Just so it is with the chord of the sixth and fourth, which derives its name from its containing those intervals. Ex.
![\new PianoStaff << \new Staff \relative { \time 4/4 \override Score.TimeSignature #'stencil = ##f <e' g c>1 \bar ".." <e c' e> \bar ".." <e c' g'> \bar ".." } \new Staff { \clef bass g^\markup { \teeny { Fourth position. } } g^\markup { \teeny { Sixth position. } } g^\markup { \teeny { Octave position. } } } >>](http://upload.wikimedia.org/score/e/w/ewxwufulm556wlez72dm9jifhtr0ys0/ewxwuful.png)
It is very necessary to know all these chords readily in their different forms.
All this equally applies to minor keys, if, instead of E♮, we every where take E♭.
These two chords are less perfect than the common chord, because, although they are tolerably agreeable, they do not sound so satisfactorily as to enable us to make a close or cadence by means of them.
Although the perfect common chord may occur on each degree of the diatonic scale