If you follow the link above to what Beato says it is that almost everything popular is being written in the 1564 progression

It refers to Nashville Numbering, and essentially says root relative minor fifth above the root to fourth above the root

so in C it is C G Am F
in G it is G D Em C

You are doing a 1645 progression with G Em C D which going to C would be C Am F G .....essentially another simple 4 change arrangement where you can re arrange...like I can take the 1564 then next play the 1645 or as Sir Paul says ...one unique chord in the chorus

Here is a link to a guide I created. If you know the basics of music you will appreciate it. I made it for myself, then threw it up on dropbox for a private facebook songwriter group I belong to
https://www.dropbox.com/s/9e1aevkszs4ae18/MusicReferenceGuide2020.pdf?dl=0


What Beato says is that the intricate is gone

FDs is right in that Beato is a great source of info. Among all the stuff one can "Youtube" vs "Google", he stands out with what he talks about and what he knows. His deconstructions and artist selections are really interesting and worht watching

If writing ever becomes work I think I'm going to have to stop