By Jeffão Peres
Tétrades
Maior com 7° Menor
D7 G7 C7
G--------2--5--------------------------------3--
D-----4---------------------3--------------5----
A--5------------------2--5----------3--7-------
E------------------3-----------------------------
Menor com 7° Menor
Dm7 Gm7 Cm7
G--------2--5-------------------------------3--
D-----3--------------------3--------------5----
A--5-----------------1--5-----------3--6------
E------------------3----------------------------
Maior com 7° Maior
D7+ G7+ C7+
G-------2--6--------------------------------4--
D----4---------------------4--------------5----
A--5-----------------2--5-----------3--7------
E------------------3----------------------------
Obs. Tônica
III, III-
V
VIIm, VII+