OK, now we want to expand our chord vocabulary a bit. We are
going to look at some specific chords, but we also want you to understand how the chords are built, so you can
figure out the ones we do not show here, and so you will better understand how they fit into progressions of
other kinds of chords.
Now, remember from our discussion of triads that we build chords,
in the most basic understanding of the concept, from odd number intervals of the key we are building the chord from.
So for a major triadic chord, by definition, we want to select the first, third, and fifth intervals. We are going to
continue with this same concept and extend it to include the seventh interval note.
For simplicity we will start with a C Major Seventh, since the
C major scale has no sharps or flats. So according to the interval relationships we learned previously, the notes of
the C major chord are C, E, and G. Now, in accordance with the name of this chord we are building, Major Seventh, we are
going to add the seventh interval note for a four-note chord. The new extra note will be a B note. So here is what our new
chord looks like.
You will see this chord type labeled in various ways:
CM7, Cmaj7, C7
Now let's take a look at the Dominant Seventh Chord. You will see
this chord often in blues style songs, and it shows up in other types of common chord progressions as well. It has a tense
sound. We construct this chord type by adding the seventh interval note, as the name implies, but also flatting
this seventh note by one half step. So in the case of our C Major Seventh Chord above, we want to change the B note
to a Bb (B flat).
You may find this fingering hard to master at first. Keep working on it and
you will get it.
You may have noticed that we dropped the fifth
interval note completely out of the chord and replaced it with our new Bb note. As chords get more complex we find
that we simply do not have enough fingers, and strings in many cases, to include all the notes that should be in a
chord by definition. In these cases we want to include as many notes as we can, and we emphasize choosing notes that
heavily influence the overall sound of the chord. In the case of our Dominant Seventh chord the fifth interval
note does not make a significant impact on the overall sound, so we drop it in favor of the flat seventh note, which
does make a major difference in the overall sound.
This chord type can add a bit of useful tension when used as the V chord in a I-IV-V progression.
It is also a great chord type to use for I, IV, and V if you want to play a blues style song. Below is a chart containing the Dominant Seventh Chords in
the open position. We will look at some alternate fingerings of these useful chords further in the Advanced section of the course.