The Role of Chords Within Keys
Each chord or chord function in a key is not created equal. You may have noticed that the I chord in Figure 5-6 feels like home when you end on it at the end of the exercise. In a very real sense it is home! All the musical elements have conspired, in total, to psychologically construct that ending G to feel like home and to give a sense of emotional closure. Again, the basic element that manipulates your emotions comes from the fact that all the chord functions use the notes of this particular major scale (G major). Thus, the G chord is preeminent, and all the other chords play a more or less subordinate role. The I chord in any key will create the same emotional sense of closure as long as the key center is revealed through a series of chords that are related to the I chord's major scale.
The I chord is not the only chord to play a specific role in a progression. Sometimes the roles of the other chords are pronounced; sometimes they are concealed. In highly predictable pop music, or even classical, the other chord functions can behave in a stereotypical role, much the same way actors might in a drama. Because the vi chord is derived from the sixth scale degree and is the tonic of the relative minor (see Chapter 4), it can sometimes sound like the I chord's evil twin. This is especially true when it serves as the beginning of a new musical section. The IV chord can serve as a complement to the I chord, or a home away from home in many circumstances. Other times, chord functions can have a push or pull effect to other chord functions. For example, the ii chord often likes to progress to the V chord, while the iii chord is often drawn to the vi or IV chords. These tendencies have at their core real theoretical underpinnings that will be discussed later on.
Reading Roman numerals I, ii, iii, IV, V, and vi in A major
This key signature (A Major) uses three sharps: F-sharp, C-sharp, and G-sharp.
There are different conceptual frameworks that can serve both to analyze and inspire different kinds of chord progressions. Random chord progressions (I-iii-V-vi-IV) seem to follow no discernable framework at all, although often, through closer inspection, fragments of some organization can be drawn out.
Figure 5-8 uses three kinds of chord progressions. It also employs arpeggios or broken chords. Measures one through four employ linear progression concepts. Measures five through eight employ fourths progression concepts. Measures nine through sixteen employ a mixture of any or all of these as well as random chord progressions. Notice that you are still employing these in a manner consistent with the overall diatonic triad scheme presented earlier in this chapter.
Figure 5-8. Etude in F major — three kinds of chord progressions.
This key (F Major) uses one flat — B .
Remember, the musical alphabet is only seven letters long. If you number them one through seven, or I through vii for chords, and cycle through them, you will get a musical number line as follows: I, ii, iii, IV, V, vi, vii, I, ii, iii, IV, V, vi, vii, and so on. So the progression (iii-vi-ii-V-I) simply moves through a cyclical musical number line inclusively by fours.