Description
The process of stacking triads can be continued beyond 1st-3rd-5th! The next interval to add is the 7th. Harmonizing beyond the basic triad is called an extended harmony chord. These are advanced chords, but I want to include them for the sake of completeness.
If you want to know more in depth about extended harmony chords, including 7ths and beyond, I have other tutorials that cover this topic in detail. For the purpose of this tutorial we'll just cover the resultant harmony of each chord as harmonized by the major scale.
Notice that adding the 7th to each chord doesn't change the quality (major, minor or diminished), nor does it change the function of each chord. The only thing we add is the 7th degree of each scale!
We get 2 major 7th chords, on the I & IV chords.
We get 3 minor 7th chords, on the ii, iii & vi chords.
The most interesting effect is on the dominant chords. We get a dominant 7th chord on the V chord & a half diminished chord on the vii. Notice that the dominant 7th chord happens when we harmonize the dominant chord, the V! That's why it's the dominant & it makes for a great way to remember this chord & function.
The half-diminished chord is more frequently used in classical & jazz than popular music. And it's also called the minor 7th flat 5th chord, because those are the scale degrees used to form it.
Lesson Info
