25.1Start with the tonic minor

Plain:

Cm

Notes:

C E♭ G.

Now add a major 7:

Cm(maj7)

C E♭ G B.

Then:

Cm7

C E♭ G B♭.

Then:

Cm6

C E♭ G A.

The bass/root stays C.

One inner voice moves:

C → B → B♭ → A

That is the classic minor line cliché.