A Player's Guide to Chords and Harmony (14 page)

The term "leading tone" almost always refers to the single note below the tonic, not to a chord built on that note. This note is called the leading tone because in a V-I progression, the 3rd of the V chord almost always moves upward to the root of the I chord (see Figure 4-7). In the natural minor scale (see Chapter Seven), the note below the tonic is sometimes referred to as the subtonic, because it doesn't tend to move upward to the tonic.

Other than in classical music, chords are seldom built using the leading tone as a root, because the diminished triad is felt to be too unstable. Rock songs often use the major triad built on the lowered VII, however. In classical music, the VII triad sometimes substitutes for a V7 chord (see Chapter Five), because it contains all of the notes of the V7 except the root. In this usage the VII chord is almost always in first or second inversion.

Figure 4-7. The leading tone (B in the key of C major) gets its name from the fact that in a V-I progression, the leading tone almost always moves upward to the tonic.

FIGURED BASS

Musicians in the Baroque period had a system of symbols that could be used for writing out chord charts. Just as jazz players do today, harpsichordists and other instrumentalists would improvise their own parts based on the symbols in the chart. This system, which is called figured bass, is of very little practical value today unless you happen to be a harpsichord player, but it's worth mentioning, if only because you may encounter it somewhere along the line, such as in a college-level textbook or test.

Figure 4-8. Baroque musicians used a system called figured bass to indicate chord parts. As explained in the text, a "6" below a bass note indicates that the chord is in the first inversion, "6 4" means second inversion, and "2" indicates a 7th chord in third inversion. The bass part shown in (a) might be realized by a harpsichordist in the manner shown in (b).

Figured bass consists of a notated bass line with numbers below certain of the notes, as shown in Figure 4-8. The system of figures, which is sensible enough, if a bit abstract, was later applied by music theorists to the system of indicating chords with Roman numerals. The same numbers that had been used in figured bass were placed to the right of the Roman numeral, thus indicating in a compact way the root of the chord (the Roman numeral), its inversion, and any additional notes contained in the voicing.

A Roman numeral to which figured bass numbers have been attached may have a small superscript number beside it, or in some cases both superscript and subscript numbers. A chord in first inversion has a superscript "6" beside the Roman numeral. This indicates that the interval between the bass note and the root is a 6th. For instance, a 1116 chord in the key of D major would be an F# minor chord in which the A is in the bass (so that the interval between the bass and the root is a 6th). The basic idea is that in the absence of any numbering, the expected chord will have notes a 3rd and a 5th above the bass, so any deviations from this pattern will be noted.

A chord in second inversion uses both a superscript "6" and a subscript "4" (for instance, I;), because the notes above the bass are, respectively, a 6th and a 4th above it, rather than a 5th and 3rd. Chords containing 7ths, which will be introduced in the next chapter, can also be indicated with this system. A rootposition 7th chord has a superscript "7" (for instance, IV). A 7th chord in first inversion has a superscript "6" and a subscript "5" In second inversion, a 7th chord has a superscript "4" and a subscript "3" In third inversion, a 7th chord is indicated with a superscript "4" and a subscript "2," or just a subscript "2" by itself.

Now that you've learned about figured bass, feel free to forget about it. Once in a while you may hear a classically trained musician refer to a first-inversion 7th chord as a 6-5 chord, or to a second-inversion triad as a 6-4 chord, but other than that, the system is pretty much obsolete once you step outside the college classroom.

THE IMPORTANCE OF THE TONIC

In Chapter One we talked about constructing a major scale starting on any note in the chromatic scale. I showed how key signatures derive their names from the note that's the tonic of the major scale played using that key signature. For instance, the B6 key signature (which contains two flats, one on B and the other on E) allows us to notate a B6 major scale without using any accidentals. The tonic of the key is important not just for defining the starting point of the scale, but because the triad built on the tonic chord - that is, the I chord - provides an important point of reference in any chord progression in that key.

In the discussion that follows, I'll use the word "tonic" to refer not to the root note of the key but to the entire triad (or, potentially, a more complex chord) built on that root. The same type of usage is used for the dominant and subdominant: These words more often refer to whole chords than to scale steps.

The tonic is a sort of anchor or resting point. Many songs - perhaps a majority - use chord progressions that both begin and end on the tonic. And when chords other than the tonic are used, they're often part of a progression that is moving either toward the tonic or away from it.

This fact opens up some interesting compositional possibilities. A composer can add tension to a chord progression by violating our expectations with respect to the tonic. For instance, a piece might not begin on the tonic. As a young man, Beethoven served notice to the audiences in Vienna that he was a force to be reckoned with by beginning his Fitst Symphony not on the tonic but on a somewhat distant chord. In the pop realm, the jazz standard "Autumn Leaves" uses the same technique.

Next to the tonic, the most important diatonic chord is the dominant - the V chord. From the 18th century onwards, the chord progression V-I - a dominant followed by a tonic - has been the most important progression in European/ American music. This progression strongly emphasizes the tonic as a point of rest. Consequently, the dominant chord is felt to provide a kind of tension that demands resolution through movement to a tonic. Many classical symphonies in the late 18th and early 19th centuries ended with a string of dominant-tonic progressions; a typical example is shown in Figure 4-9. This type of ending hammered home the tonic as the final resting point in the piece.

Next in importance to the dominant and tonic is the subdominant. Looking at Figure 4-9, you might think this note/chord gets its name from the fact that it's the scale step below the dominant ("sub-" is a Latin prefix that means "below"). But in fact the name is derived from the fact that the dominant is a 5th above the tonic, while the subdominant is a 5th below the tonic.

Figure 4-9. The dominant-tonic (V-1) progression is the most important progression in the classical music of the late 18th and early 19th centuries. The progression shown here, which alternates V and I chords in the key of C, illustrates how a symphony written in this period might come to its thrilling conclusion.

In music of the late 18th and early 19th centuries (the so-called Classical period in classical music), the subdominant was often deployed just before the dominant in a progression leading back to the tonic. This IV-V-I progression is shown in Figure 4-10. This progression is still used in many modern pop tunes, especially in country and folk music, which tend to use relatively simple changes. In jazz and jazz-derived styles, however, the IV has been largely supplanted by the minor II chord, also shown in Figure 4-10. If you play these progressions, you should be able to hear that the IV chord (the subdominant) and the minor II chord are similar in sound, and perform a similar harmonic function. The minor II chord in first inversion was often used in place of the IV chord in Classical progressions as well.

Figure 4-10. The IV-V-I progression, used in traditional classical music, and the II-V-I progression, used more often in jazz, are similar.

PHRASES & CADENCES

It's useful to look at a piece of music of any significant length not as a single seamless entity, but as a series of phrases. The end of each phrase flows into the beginning of the next, usually without a pause. The most common lengths for phrases are four and eight bars, but odd-length phrases, such as five or ten bars, are by no means unusual.

The division of a longer piece into phrases usually feels very natural. As you listen to music, you'll probably be able to identify phrases without trouble. If you're in doubt, when looking at sheet music, about where one phrase ends and the next begins, try counting out groups of four or eight bars. Chances are, you'll be able to find the phrases this way.

The portion of a chord progression that ends a phrase is called a cadence. As you can probably anticipate from the section above on "The Importance of the Tonic," many cadences end on the I chord. A cadence in which the I is preceded by a V (for an example, see Figure 4-9) is called a full cadence or an authentic cadence. But not all cadences are full cadences. For that matter, not all V-I progressions are cadences. A cadence is specifically what happens at the end of a phrase.

If the last chord in the phrase is a V chord, the cadence is called a half cadence. Figure 4-11 shows a simple progression in the key of G in which the first four-bar phrase ends on a half cadence on D (the dominant of G) and the second four-bar phrase on a full cadence. A cadence in which the I is preceded by a IV rather than a V, as in the "Amen" that ends many hymns, is called a plagal cadence.

If all V chords were followed by I chords, the world would be a dull place. Composers often trick their listeners by leading up to a V chord and then following it with something other than a I chord. This is called a deceptive cadence. The chord most often substituted for the I in a deceptive cadence is the VI (see Figure 4-12). One reason the VI is often chosen is because the VI and the I share two notes (the tonic and mediant), which makes the substitution sound natural. Another reason is because the VI is a minor triad, whose piquant sound adds meaning to the deceptive cadence. Other chords can be used in deceptive cadences, as Figure 4-12 suggests.