Interesting thread.

It always amazes me that people don't get what all decent guitarists know.

The chords and therefore the form of George Formby's cleaning windows is very similar to Blind Blakes Rag, hugely similar to Sporting Life Blues/ Ain't Nobody's Business done by Billie Holiday and Brownie McGhee. George Gershwins Someone to Watch Over me
Very Similar to Fats Wallers Ain't Misbehavin'
Not totally unlike the unaccompanied Dinks Song.
The Call and Response rather similar to Scarborough Fair.

I mean, really there's damn all pure about it.
It all leaks into each other.