10.11Stack-of-thirds method

Another way to understand seventh chords is by stacked thirds.

Cmaj7

C → E = major 3rd

E → G = minor 3rd

G → B = major 3rd

Pattern:

major – minor – major

C7

C → E = major

E → G = minor

G → B♭ = minor

Pattern:

major – minor – minor

Cm7

C → E♭ = minor

E♭ → G = major

G → B♭ = minor

Pattern:

minor – major – minor

This is useful, though for practical playing I prefer the scale-degree formulas.