Most Influential American Musician of All Time?

The Beatles were not American.

And was Elvis really a musician?

and was Elvis really a musician?

That's funny.

Uru975 has the correct Double Jeopardy answer with Gershwin. While my vanity plate reads SATCHMO, and he is a monster in terms of influence and creativity, Gershwin's reach internationally was/is so great. And besides, consider all of the greats doing "__________ Sings the Gershwin Songbook".

Robert Johnson is an inspired choice, particularly since his influence is based on so little recorded music and since he died so young. Had he lived longer and recorded more, I expect more people would understand how influtential he was on rock music. It's amazing that his influence didn't really even begin until he was "discovered" over two decades after his death.