A Player's Guide to Chords and Harmony (33 page)

nlike triads and 7th chords, all of which can be listed and explained, the number of possible chord progressions is infinite. Even the number of fourmeasure progressions in 4/4 in which the chords change only at a quarter-note rate is so large it makes my head hurt. As you write your own music or play music written by others, you'll constantly encounter fresh variations. That's what makes chords and harmony so useful.

Even so, certain types of progressions have been used over and over by various composers, to the point where they've become part of the common vocabulary of harmonic music. So it would be premature to end this book without taking a quick look at a few of the standard chord patterns you'll encounter again and again in your musical life.

BLUES PROGRESSIONS

The blues scale was introduced in Chapter Seven. But there's another side to the blues, which is arguably even more basic than the scale: Most blues songs use some variation on a common chord progression. In its classic form, this progression is 12 bars long. Musicians often refer to it as "12-bar blues," or even just "12-bar" This progression is widely used in jazz, rock, and other genres as well as in the blues genre itself.

The most basic form of the 12-bar blues progression is shown in Figure 8-1. It's seldom played in precisely this way, but the underlying structure shown is implicit in almost any blues progression you'll encounter. The progression consists of three four-bar phrases. The first phrase is centered on the I chord. The second phrase starts on the subdominant and returns to the I. The third phrase starts on the dominant, and again there's a return to the I. The entire 12-bar progression is called a chorus. (For more on this term, see below.)

Figure 8-1. The underlying structure of 12-bar blues uses three four-bar phrases. Most actual blues progressions have one or several added chords not shown here.

If you take a look back at Figure 4-9, you'll see that it shows an eight-measure progression which is divided into two four-measure phrases. This structure, in which a complete musical idea is built out of two phrases of more or less equal length, is called a binary form. Some binary-form phrases are only eight bars long, but others are quite a lot longer. Binary form is hundreds of years old, and is used in everything from Renaissance lute music to punk rock and beyond. One of the things that's interesting about the blues is that the full 12-bar phrase is not binary: The 12-bar blues has a ternary (three-part) structure. Blues is the only form of Western music I'm aware of that regularly uses a ternary phrase structure.

Figure 8-1 is a prototype of the blues progression. More typical of blues and blues-derived rock songs is the slightly more complex progression shown in Figure 8-2. In many blues songs, all of the chords in this example would be played as dominant 7ths. There are three differences between this progression and the one in Figure 8-1:

• A IV chord has been added in bar 2.

• Another IV chord follows the V chord in the third phrase, leading back to the I.

• In the last two measures, the chords change more quickly. These measures are called the turnaround, because they provide an added impetus that leads forward into the next chorus.

Figure 8-2. A standard blues progression as it might be played in a jam session. Compared to Figure 8-1, this progression contains an added /V chord in bar 2, another IV in bar 10, and a turnaround in bars 11 and 12. Notice that the harmonic rhythm doubles in the turnaround.

In jazz, the V and IV chords in bars 9 and 10 are generally replaced with a IIm7-V7 progression. In addition, the turnaround is often played with some type of back-cycling (a progression that moves through a couple of II-Vs or a circle of secondary dominants). A basic jazz blues is shown in Figure 8-3.

Figure 8-3. A typical jazz blues progression. In bar 4, the Vm7 and 17 function as a II-V leading up to the IV chord in bar 5. Likewise, the IIm7 chord in bar 9 is preceded by its own secondary Il-V. The turnaround (bars 11 and 12) contains two more 11-V cycles. Note also that the I chord is not played at the beginning of bar 11. Instead, it's delayed until the beginning of the next chorus.

Composers often substitute other chords at strategic spots in the blues progression. A 6VI7, for instance, can substitute for the 1V7 in bar 5. The well-known Miles Davis tune "All Blues" (which happens to be in 6/4 rather than 4/4) uses the progression in Figure 8-1, but bar 10 shifts up to a 6VI chord, falling back to the V in the second half of the bar. In addition, there's some internal movement of voices above the IV root. These extremely simple variations give the tune a distinctive quality that would otherwise be lacking.

Not all blues uses a straight 12-bar framework. In folk blues, whether played on guitar or piano, musicians sometimes add or drop a bar, or even add or drop one or two beats, usually at the end of the four-bar phrase. Stretching and bending the form in this way can give the song a strong emotional impact. Another variant doubles the length of the initial section on the I chord. This is done in many rock and roll songs, so that a four-line verse can be sung over the I. Both the double-length I section and two added beats are used in a Little Richard hit called "Good Golly, Miss Molly" The lyric hook (the title) is sung during an extra twobeat rest that precedes the IV chord.

VERSE, CHORUS & BRIDGE

The term "chorus" is used by pop and jazz musicians in rather different ways. The term has the same underlying meaning in both genres - the chorus is the memorable part of the song, the part you hope audiences will be humming when they leave the venue after the gig. But the term underwent a sort of transformation in the jazz world.

Jazz as we know it today is an outgrowth of the popular music of the 1920s and 1930s. Many of the popular songs in those bygone days started life as show tunes in Broadway stage musicals. Songs in Broadway shows typically had a verse/chorus structure. Unlike pop music today, though, there was usually only one verse. It was often somewhat introductory in nature, perhaps being sung in a free rhythm over sustained chords. The band or pit orchestra would then enter with a strong beat at the beginning of the chorus. When these tunes were played as instrumentals by jazz bands, the verse, which wasn't very interesting to begin with, was often dropped. Thus, jazz tunes consisting of nothing but a chorus became the norm.

A typical jazz chorus is 32 bars in length, and consists of four eight-bar phrases. The opening eight-bar phrase is played and then repeated, sometimes with small variations. After this 16 bars comes a contrasting eight-bar phrase, called the "middle eight" or "B section" The original eight-bar phrase is then repeated a third time, rounding out the form.

Diagramming the Form of a Song. Musicians often give letter-names to the phrases within a song structure, so the structure described above - an eight-bar phrase which is repeated, then a contrasting phrase, and finally the return of the first phrase - is an AABA form. When the form of a song is diagrammed in this way, each letter stands for a separate phrase, and it's reasonable to assume that all of the phrases are the same length (usually four or eight measures). If a section is repeated in a way that's essentially the same as before, but with small variations, the diagram might use subscript numbers to indicate the differences: You might see a song form described as AA1BA2, for instance, if each repetition of the A section has some variation.

In a piece in which there is no contrasting B section, such as a 12-bar blues or a classical movement in theme-and-variations form, the structure might be diagrammed as AA 1 A2A3A4.... Conversely, a piece in which each section was radically different from what had gone before would have to be diagrammed (if there were any reason to diagram it) as ABCDE....

AABA form is by no means a universal structure for songs that are part of the jazz mainstream. You'll encounter many variants - 32-bar tunes with no middle eight, for instance. (The songbook of the band I'm playing in at the moment includes two beautiful jazz tunes of this type: "All of Me" and "Black Orpheus") The progressions of such 32-bar tunes may start with an eight-bar phrase, answer it with a different eight-bar phrase, then repeat the first phrase and round out the form with yet a third phrase. This is ABAC form.

When jazz musicians solo over the changes of a standard tune, each soloist will typically take the spotlight for one or several complete choruses, each chorus consisting of the full 32-bar progression. If the performance of the tune is organized in such a way that it begins and ends with a melodic instrument playing the original melody, with improvised solo choruses in between, the musicians may refer to the chorus that contains the original melody as the "head." This is a shortened version of the term "head arrangement," which originally referred to arrangements that were more or less fixed in form, but that weren't written out. They existed only in the musicians' heads.

In pop tunes from the more modern rock tradition, the idea of the verse is still very relevant. Most pop songs today use a structure that alternates verses with choruses. The chord progression used in the verse may or may not be different from the progression used in the chorus. What distinguishes the two is that the lyrics of each verse in the song tend to be different, while the lyrics of all of the choruses in the song tend to be the same. If such a song has three verses, each followed by a chorus, it's in ABABAB form.

In order to provide a little variety, pop songs very frequently have some sort of break after the second chorus. This might be a short instrumental interlude; it might be a longer section in which instrumental solos are played over the chords of the verse, chorus, or both; or it might be a contrasting section in which further lyrics are sung, usually over a different progression than either the verse progres Sion or the chorus progression. The latter type of section is called a bridge. It's also called a B section, but this term is a bit misleading. If we diagram a song that has verses, choruses, and a bridge after the second verse, the form would be ABABCAB, making the bridge the C section. (Nobody calls it that, however.)