Oh, I have the solution. "Americana." I have a friend who teaches musicology. He says, at this point, especially if you just look at the 20th century, all these genres are clearly boiling together. That is a classic piece of "Americana" music. CCR period is an entire category of Americana.
If things get too "off beat" it can't be Americana. The tune has to "resonate" with the tradition of American music.
And if you are talking songs that focus on the singer, then it's "part of the great American Songbook." Everything from Sinatra to Paul Simon.
Hope that helps. Here's some Canadiana:
(edit: if you really just need a cookie, go straight to 5: 59)