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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:
Just so it is with the chord of the sixth and fourth, which derives its name from its containing those intervals. Ex.
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