It is possible to place, one after the other, both the Real Triad and the deceptive triad of the same seventh Tetrad, in root position, giving the impression of a progression by ascending third. This is the normal order, the Real Triad first, without the seventh, followed by the deceptive triad, with the seventh. However, cadential priorities will at times favor the opposite order, to produce the Fundamental Bass. The two basic Tetrads involved will be that ofI⁺⁷ with its Real Triad ofIand its deceptive triad ofiiiproducing the(I-iii)-IVchord pattern and that ofV⁷ with its Real Triad ofVand its deceptive triad ofviiproducing the(V-vii)-Ichord pattern (the two triads have been placed in parentheses to show that they belong to the same Tetrad and that there is no progression involved). The(IV-II)-Vpattern which we saw inClass 4will act as a link to establish a complete pattern(I-iii)-(IV-II)-(V-vii)-I, from the basic TetradsI⁺⁷-IV⁶II⁷-V⁷-I.

I-iii-IV and V-vii-I

Doubling and Voice-leading Lines
The four VLLs have been written ins
     to clearly indicate that they belong to the same basic Tetrad
          and that there is no veritable progression between them.

The(I-iii)-(IV-II)-(V-vii)-Ichord pattern -
     NOTE, in(I-iii), the EG in VLL 2
          which prevents doubling the E of VLL 4 and doubles the G of VLL 1,
               while VLL 3 "passes" the seventh ofI⁺⁷ .
     NOTE, in(V-vii), the BD in VLL 3
          which prevents doubling the B of VLL 4 and doubles the D of VLL 2,
               while VLL 1 "passes" the seventh ofV⁷ GF.
     Thevii-Icadence is weaker than theV-Icadence
          because it does not have theFB(GC) in VLL 4.

The(I-iii)-(IV-II)-(vii-V)-Ichord pattern, with theFB(GC) in VLL 4,
          by inversing the position ofVandvii-
     NOTE that -
           II-vii, by descending third,
               is a true progression, part ofII⁷-V⁷ , but
           (vii-V), also by descending third,
               is not a true progression, only parts ofV⁷ .
     NOTE, in(vii-V), the DB in VLL 3
          which replaces the lost B of VLL 4,
               while VLL 1 loses the seventh ofV⁷ substituting the root FG,
                    which resolves to E as the seventh F would have done.
This second example has a stronger cadence than the first one.

V-iii-IV

Doubling and Voice-leading Lines
Here is another interesting example of a true progression by descending third,
     this one based on two Tetrad progressions by descending fifthV⁷-I⁺⁷-IV,
          theiiibeing a deceptive triad ofI⁺⁷ .

TheI-(IV-II)-V-iii-IV-V-Ichord pattern -
     NOTE the ascending lines in the first half,
          and the descending lines in the second half.
The note G in VLL 3 may be an octave higher, but the crossing with VLL 1
     will impose disposition in the soprano and tenor voices.
True progressions by descending third (likeV-iii)
     will be common practice in the circle
          when Real Triads and deceptive triads alternate.

Melody
More interesting and fruitful VLLs here.

On toThe Circle
and later toClass 10