2.20Now transpose a chord progression

Take:

C → Am → F → G

In C this is:

I → vi → IV → V

Now move it to G major.

G major's chord family:

G Am Bm C D Em F♯°

Therefore:

I = G

vi = Em

IV = C

V = D

So:

G → Em → C → D

Move it to F:

F major:

F Gm Am B♭ C Dm E°

So:

I = F

vi = Dm

IV = B♭

V = C

Therefore:

F → Dm → B♭ → C

Same harmonic progression.

Different notes.