I-IV-V Chord Progressions
Reduced to its simplest form, the blues comprises three chords. Using roman numerals, these chords are I (tonic), IV (subdominant), and V (dominant). Remember that the I chord or tonic is always your home base. What is the significance of the I chord in the blues?
All chords eventually resolve to a I chord.
Songs always begin with a I chord.
Songs almost always end with a I chord.
The I chord defines the key. For example, if the I chord is C, the key of the music is C major. If the I chord is a B-flat minor, the key of the music is B-flat minor.
FIGURE 9-1 is a review of the I, IV, and V chords in root position. (If you're reading chapters out of order, it's a good idea to go back to Chapter 6 to review the diatonic triads.) Like most of the examples in this book, the I, IV, and V chords in
FIGURE 9-1: I, IV, V Chords in Root Position
You were first introduced to these triads in Chapter 6. However, these chords were only applied as musical snippets. In this chapter, you will learn how to make music with these chords by playing over a twelve-bar blues.
A chorus is not just a vocal group. It is a musical term that means “the form” or “the structure” in music. A chorus is a musical loop. All choruses contain a strict number of bars as well as a harmonic outline. Choruses may contain any number of bars. The twelve-bar blues is a very popular type of chorus.
In FIGURE 9-2, the I, IV, and V chords have now been altered to fit nicely under your fingertips in the right hand (treble clef). The I chord remains unchanged. However, the IV chord is now changed to second position. This means that the “C” or fifth interval of the chord is placed the bottom. The V has also been changed to first position. This means that the “B” or third interval of the chord is placed on the bottom. Notice that the D or fifth interval of the chord has been left out. Because fifths are consonant, they have little harmonic value. In this case, the fifth has become an expendable note. Last, a flatted or dominant seventh (blue note) has been added to the V chord. This is the “F” seen on the first space of the staff. Be sure to note the fingerings.
FIGURE 9-2: I, IV, V Chords Voiced for the Right Hand
These chords can also be played in the left hand, although in blues piano, the left hand is usually reserved for bass lines. FIGURE 9-3 shows a I-IV-V chord progression written on the bass clef. As you may have guessed, the chords are written in a lower octave. Other than the placement on the keyboard, the notes in this figure are identical to those used in
FIGURE 9-3: I, IV, V Chords Voiced for the Left Hand
