6-4 Chords

TH101 - Seth Monahan

SIX-FOUR-CHORDS THREE PRINCIPAL USES Compared to the other inversions of triads, 6/4-chords are so unstable that they are often regarded as mildly “dissonant.” Accordingly, they are subject to very special restrictions; they are always prolongational chords, and should never appear in your writing or analyses without a clear indication of their subservient function. This handout discusses the three main types of embellishing 6/4 chords: “pedal”6/4s, “passing” 6/4s, and “arpeggiating” 6/4s.

1. PEDAL SIX-FOURs THE BASIC PARADIGM The “pedal” 6/4 is an embellishment of a 5/3 chord; it is produced by two simultaneous non-chord tones in the upper voices. More specifically, pedal 6/4s are produced when a chord’s third and fifth are displaced by non-chord tones a step higher, over a stationary bass. Example (a) shows a very clear specimen: a pedal 6/4 is created when the chordal third and fifth are each simultaneously embellished with upper-neighbor non-chord tones (shown in red). However, the non-chord tones that produce the 6/4 may arise in a variety of ways. At (b), a pedal 6/4 embellishes a submediant triad; here the non-chord tones (again in red) are accented passing tones from the preceding chord. At (c) the non-chord tones are suspensions. In all cases, the voice-leading is simple: the bass and its upper-voice doubling (here in the tenor) remains stationary, while the non-chord tones resolve by step to the nearest chord member.

6/4 produced by two neighbor notes

         

(a)

Chord root (doubled) doesn’t move

D:

I!

  

@ ped

I

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!

6/4 produced by two accented passing tones

(b)

   I

      !

vi @

ped

vi

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6/4 produced by two suspensions

(c)

   I

      !

V@

ped

V

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VARIABLE PARAMETERS •

Pedal 6/4s may be accented or unaccented, and may embellish any consonant 5/3 chord.

•

Pedal 6/4s are often “enclosed” by the 5/3 chord they embellish (as at [a]). But just as often they will appear only prior or only following the embellished chord, resulting in a two- rather than three-chord basic paradigm, as at (b) and (c).

SIX-FOUR CHORDS (p. 2) TH101 - Seth Monahan

THE CADENTIAL SIX-FOUR Examples (b) and (c) show the most widely used 6/4: the so-called “cadential 6/4,” an accented pedal chord that embellishes a root-position dominant (V). At less advanced stages, we might suppose this chord (marked with arrows below) would be called “I@,” since it contains all the same tones as the tonic chord. But like all pedal 6/4s, this one is only an “apparent” chord; it is really a collection of non-chord tones over a stationary bass. That is to say, the cadential 6/4 is simply not a “tonic” chord in any relevant sense. Its function, as determined by its bass note and as revealed by its resolution, is entirely dominant. Resolving the cadential 6/4 is easy. If you wish to move to a triadic dominant (b), simply resolve it like any other neighbor 6/4: the bass and its doubling hold still while the other two notes descend by step. Resolving to a dominant seventh (c) is just as easy; all three upper voices descend by step. (Though now the bass figures must be expanded by an extra integer to show the third moving voice.) You may also resolve the chord to a V%, as shown at (d), moving the bass away from ^5 and creating an “evaded” cadence. NOT a “I@” chord!

      

  

   

V@

!

I

(b)

D:

(c)

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(d)

motion to V7

  

° V@

   ‡!

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“evaded” cadence*

   

  

  

  

I

V@

%

Ifl

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Additional points about the cadential 6/4: • •

^ with As examples (b) and (c) show, cadential 6/4s allow us to harmonize the melodic progression 3^ - 2^ - 1 a simple V – I bass. Being accented dissonances by nature, cadential 6/4s typically appear on strong beats (1 or sometimes 3). However, in triple meter they may appear on either beat 1 or 2.

NOTATING PEDAL SIX-FOURS*** When labeling pedal 6/4s, upper-voice embellishments are shown with a change in the figured bass intervals, but the Roman numeral does not change. This can be a bit confusing; the effect is that pedal6/4s cause the figured bass and Roman numerals briefly to go “out of sync.” The bass figures capture the non-chordal motions in the upper voices, but the Roman numeral always corresponds only to the parent chord, and never to the “apparent” chord produced by the NCTs. Looking at just the analytic figures of (a) (I! - @ - !), we might imagine that the middle chord was a “I@.” But in fact the chord contains ^1, ^4, and ^6; taken literally, this is a IV@. But the point of this notation is that we are not to take the chord “literally.” We don’t label it IV@ because it is only an apparent chord, produced by local voice-leading; there is no “real” change of root. This same principle applies to incomplete neighbors. Note that at (b), the analytic notation (V@ - !) seems to suggest a “V@” chord, which is clearly not the case. (For that we would need ^2 in the bass.) This is simply a V chord briefly embellished by a @ - ! motion in the upper voices.

* Note that the dotted lines between the bass figures at (d) do not represent the literal voice-leading resolution, as the solid lines do in (b) and (c).

SIX-FOUR CHORDS (p. 3) TH101 - Seth Monahan

2. PASSING SIX-FOURS 6/4-chords can also be used a contrapuntal chords—more specificially, as passing chords between triads in root-position and first-inversion, similar to the way we have used viio6 and several other chords. Example (e) shows a modified “X” paradigm with V@ used as a passing chord between I and I6 ; notice how similar it is in structure and function to the more familiar passing viio6 (f). This same passing-chord formula can be transferred to other triads and other bass line segments. Example (g) shows two predominant sonorities—ii and ii6—whose bass notes lie a third apart. In between lies a iv@, whose bass provides the stepwise connecting link.

Only 1 note difference (A vs. G)

   





D:

V@

Ifl

(e)

    I

(f)

 

 

 

 

  

 

I

viiøfl

Ifl

ii

 

 

(g)

 

 

vi@

iifl

(P)

(P)

(P)

I

I

ii

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3. ARPEGGIATING SIX-FOURS Sometimes a root-position triad is prolonged by several chordal skips in the bass, resulting in a full arpeggio. In such cases, a 6/4 chord is produced “incidentally” when the bass passes through the chordal fifth, as shown at (h) below. In other cases, accompaniment patterns will produce “apparent” 6/4 chords by breaking up a root-position triad into different “chunks” on strong and weak beats. We see this at (i), on beats 2 and 3. Such 6/4s—which are especially common in certain march, waltz, and folk-tune idioms—are always to be understood as fleeting embellishments of the root-position parent chord. At (h) and especially at (i), we should understand the root of that parent chord as the “real” bass note of the entire progression.

           

(h)

  

  

(i)



    



    

arp.

D:

I I

£fl

@

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D:

I CLICK TO PLAY