Adding Some Spice Through Chord Extensions
Your first introduction to playing chords dealt with learning triads. That was an important step. However, chords can become more complex and expressive than a mere three-note triad. In fact, part of the true beauty of music comes from the expression of harmonically rich chords that use extensions. The first note that crosses this threshold is the almighty seventh.
There are two types of seventh chords: the major seventh and the minor seventh. The minor seventh can also be called a dominant seventh. To avoid confusing the minor seventh and the minor triad, it is often best to use the name “dominant seventh” when describing the seventh scale degree as part of a dominant chord.
How do I find the major seventh and minor (dominant) seventh?
The major seventh is ten half steps above the root of the chord. It is also found a half step below the root. The dominant seventh is nine half steps above the root of the chord or a whole step below it.
To learn seventh intervals on the bass, play the notes in Figure 7-5, which alternate between the root and the seventh. Here the seventh is used first as a major seventh (written as
Figure 7-5.
Major and dominant sevenths
You need to incorporate this new chord extension back into the basic broken chord you learned earlier. In Figure 7-6 you'll be using arpeggios to articulate four new varieties of seventh chords. As you will see, you can combine both major and minor triads with major and dominant sevenths.
You can see that both types of triads (major and minor) can contain two kinds of sevenths (major and dominant) attached to them. Be especially careful when reading the chord symbols here. You'll want to study the symbols until you see how each chord is represented.
Figure 7-6. Four types of seventh chords.
Another chord extension that becomes important, especially in the blues and in blues rock, is the major sixth. This extension is actually the same as an interval called a thirteenth. Depending on context and taste, you may see either name used. Again, to learn the intervallic placement of this note, it's best to look at it in rotation with the root. Figure 7-7 does this both above and below the root by applying octaves.
It is crucial to understand that a “min” refers to the triad being minor while “maj” refers to the seventh being major. This is very confusing at first. If you temporarily use brackets, you will get a better picture of what is being modified: C (maj7) equals a C-major triad with a major seventh; C (7) equals a C-major triad with a dominant seventh, Cm (maj7) equals a C-minor triad with a major seventh, and Cm (7) equals a C-minor triad with a dominant seventh.
Figure 7-7.
Adding the sixth
F# is the sixth scale degree up from A!
Figure 7-8 is an arpeggio that uses the sixth, and it also sounds just like a familiar early rock-and-roll or R & B bass line. It's neat how something so emblematic of a certain style of music is based so directly on one single arpeggio (with variation).
Figure 7-8.
Arpeggiating the sixth
