Marty Stuart on Tom Petty & The Heartbreakers:

You might as well claim that when Clapton plays the Blues, it's not American music because he was born in the UK. That strikes me as absurd. 

Let’s just think of (U.S.A.) Americans and Canadians as North Americans. ;-) . I would argue that in some ways Americans from the North (or at least non-South) have more in common with Canadians than they do with Southerners.

Levon Helm---born and raised in Arkansas---was the heart and soul of The Band (though Richard Manuel was very soulful), his voice a major element of their trademark sound. The other members of The Band cite American songwriters, singers, and musicians as their role models.

Do people think of Neil Young as an American artist, or a Canadian one? How about Joni Mitchell? Leonard Cohen? The Guess Who? Steppenwolf?

@bdp24:

"Let's just call both (U.S.A.) Americans and Canadians as North Americans. ;-) ".

Sure. Why not? 

   "I would argue that in some ways Americans from the North (or at least non-South) have more in common with Canadians than they do with Southerners"

You could very well be right. I've almost no exposure to the South so I can't say. My wife and I have been on 3 vacations to Canada, though and we love it up there. 

"Do people think of Neil Young as an American, or a Canadian? How about Joni Mitchell? Leonard Cohen?"

Tough calls for me. I'd bet all three were heavily influenced by American music but the question is: are their artistic sensibilities more Canadian or American?  ?  ? Above my pay grade, I'm afraid.  That's perhaps a question for a serious academic. 

And bizarre as it may seem, Lowell George “ a master of rhythm, a rock n roll King “…. Played w Zappa…

I prefer fewer but soulful notes

The Holmes Brothers always played at a very high level.  Due to multiple deaths they no longer exist, but they were one of the best.