2. The Usage of the Dominant Seventh Chord
In the previous blog (Understanding Basic Harmony) we worked with three-note chords (triads). Now we will venture into the world of four-note chords. However in this blog we will start with the fifth (V) step of each scale. In C major our fifth step is G. The chord is G major (G-B-D) and when it receives the note F on top it becomes a dominant seventh chord. The symbol receives a 7 next to the capital letter, therefore G7.
One way to easily learn all dominant seventh chords is to look at all the major chords and add on the fourth note which is exactly two half steps lower than the first note. Whole steps are the distance of two adjacent notes and a half step is only the distance of an adjacent note. With C major we can look at the octave C and going two adjacent notes lower we receive Bb.
Therefore C7 looks like this (C-E-G-Bb).
In traditional music the dominant seventh chord moves from the fifth step to the chord on the first step. Therefore the chord movement we all know very well, G7-C. In the age of the Baroque this chord relationship went through a transformation bringing the secondary dominant into existence.
In the first paper we learned of the seven steps and the three-note chords that appear on each step. The baroque began using “borrowed” dominants to resolve to each step of the major or minor scale. These are the dominant seventh chords we call secondary dominants. Without any further ado I will now give the row of secondary dominants as they appear in C major and A minor.
As I have explained the normal relationship is G7-C. In Roman Numerals this stands as such (V7-I). As we can decipher the dominant is built on the fifth step of the major scale. Therefore G dominant 7th moves to C major. Now we will place a dominant 7th before every step of the scale and resolve it to the three-note chord found there. Therefore always a dominant seventh chord built five scale tones higher than the coming chord.
G7(V7/I)-C(I) ; A7(V7/II)-Dm(II) ; B7(V7/III)-Em(III) ; C7(V7/IV)-F(IV) ; D7(V7/V)-G(V) ; E7(V7/VI)-Am(VI); F#7(V7/VII)-B dim(VII) In minor the same relationships exist but they are simply analyzed differently.
E7(V7/i)-Am(i) ;F#7(V7/ii)-B dim(ii) ; G7(V7/iii)-C(iii) ; A7(V7/iv)-Dm(iv) ; B7(V7/v)-Em(v) ; C7(V7/vi)-F(vi) ; D7(V7/vii)-G(vii)
The word cadence is perhaps new for some of us but it simply means a progression of at least three chords that resolve after a dominant. Therefore the placement of another chord before the dominant. An example could be Dm(II)-G7(V7/I)-C(I). This relationship is found often especially in jazz standards. I have added the minor chord that begins on the second step. This cadence we can use with the destination being a major chord. For example Gm(II/IV)-C7(V7/IV)-F(IV) or Am(II/V)-D7(V7/V)-G(V).
Looking at the second chord of the minor we see we have the diminished chord. This will be the (II) chord for this cadence with the destination being a minor chord. This looks as such: B dim(II/VI)-E7(V7/VI)-Am(VI).
Now I will write the cadence as it resolves to the other minor chords on step (II) and step (III). Edim(II/II)-A7(V7/II)-Dm(II) ; F#dim (II/III)-B7 (V7/III)-Em (III). All of these cadences can be used in either C major or A minor. An example in the literature is Ray Charles’ refrain to “Let’s Go Get Stoned.” C(I)-Bdim(II/VI)-E7(V7/VI)-Am(VI) ;Gm(II/IV)-C7(V7/IV)-F ; Dm(II)-G7(V7)-C(I).
When we follow the Roman Numerals we can begin to transpose this knowledge into other keys. Now I will guide us through a transpositional process. G7(V7/I)-C(I) ; A7(V7/II)-Dm(II) ; B7(V7/III)-Em(III) ; C7(V7/IV)-F(IV) ; D7(V7/V)-G(V) ; E7(V7/VI)-Am(VI) ;F#7(V7/VII)-B dim(VII) was our original row of secondary dominants.
We will use the Roman Numerals to help us find each new chord say in the Key of F. The basic dominant 7th chord going to the (I) chord in “C” is G7(V7)-C(I). C7(V7/I)-F(I) is the transposition in that C is the fifth step of F major and F being the first step. This is how a formula in Roman Numerals translates into a transposition. G is the second step in F major and G minor is the chord on the second step. As I stated before, five notes higher from the “G” , in this case, is where the secondary dominant will be built. Therefore the V7 of the (II) step (G-A-Bb-C-D) is D7. One further example is A as the third step of the F major scale and A minor is the (III) chord. Once again, five notes higher from “A ” is where the secondary dominant will be built. Therefore the V7 of the (III) step (A-Bb-C-D-E) is E7.
Finally I will move the chord progression of Ray Charles to the key of “A”. C(I)-Bdim(II/VI)-E7(V7/VI)-Am(VI) ;Gm(II/IV)-C7(V7/IV)-F ; Dm(II)-G7(V7)-C(I) was the example of cadences using the addition of the (II) chord before the (V7 ) and then resolving to a destination chord. In the key of “A “we start with the (I) chord A. Then we must look at the end of the cadence. All cadences are separated by a colon. Our first cadence ends on Am in “C”. This chord is the (VI) chord and the (VI) chord in A is F# minor.
Now we will look at the formula of the cadence. The (II) chord of the (VI) chord (A minor) in “C” is B diminished. The (II) chord of the (VI) chord in “A” is one step higher than F# therefore G# diminished. Then exactly like earlier, we count five notes higher from F# and land on C# and C#7 is our secondary dominant. Therefore the first four chords can be transposed as such A(I)G#dim(II/VI)-C#7(V7/VI)-F#m(VI).
Next we have the cadence in the key of “C”which ends on F major. F major is the (IV) chord in C major. The (IV) chord in “A” is D major. Again we will look at the formula of the cadence. The (II) chord of the (IV) chord (F major) in the key of “C” is G minor. The (II) chord of the (IV) chord in the key of “A” is one step higher than D therefore E minor.
Then exactly like earlier, we count five notes higher than D and land on A and A7 is our secondary dominant. Therefore the next three chords appear as such Em(II/IV)A7(V7/IV)D(IV). Lastly the cadence back home II-V7-I. In “A” this is Bm(II)E7(V7)A(I). Our entire transposition is
A(I)-G#dim(II/VI)-C#7(V7/VI)-F#m(VI) ;Em(II/IV)-A7(V7/IV)-D ; Bm(II)-E7(V7)-A(I). The next blog we will learn about “voice leading” to insure smooth movements from chord to chord.