Major 7th Chords
Where major and minor triads have 3 different notes,
7th chords have
4. Dominant 7th chords (the most common 7th chord)
are constructed using
the root, 3rd, 5th, and the 7th scale step flattened.
For example, let's take a look at the C Major Scale:
Now let's take the Root (1st step), 3rd step, and 5th step of the scale
(in parentheses below):
In order to create a Dominant 7th chord we combine these 4 notes, except
we flatten the 7th step (drop it down 1 fret).
