Music Genius

Someone at Robert Christgau's Review blog Expert Witness tried to get a comments section going on the 10 Greatest Geniuses in Music History.  All genres included.  I almost took the bait,and then bailed because I couldn't stop at 10 and because I had trouble defining a genius.
Okay, Brian Wilson and Stevie Wonder. But is McCartney/Lennon?  Probably.  What about a Country giant like Hank Williams Sr?  Or are these types just great at what they did?  And why don't I have any Women on my rough draft?

Here's just a partial list of names, Jazz and some Classical artists, that I came up with.  It was only a rough draft:

Brian Wilson
Stevie Wonder
Ray Charles
Lennon/McCartney
John Coltrane
Miles Davis
Charlie Parker
Louis Armstrong
Beethoven
Mozart
Bach
Prince
Marvin Gaye
Sly Stone
Hank Williams Sr.
Phil Spector
Jimi Hendrix
Cole Porter
George Gershwin

etc., etc.......