4.1The basic harmonic skeleton

A common opening sequence is:

Am7 → Dm7 → G7 → Cmaj7

then:

Fmaj7 → Bm7♭5 → E7 → Am7

This is the central engine.

Look at the roots:

A → D → G → C → F → B → E → A

That is essentially the Circle of Fifths unfolding continuously.