Dave Matthews Band, you can't get any whiter than that (yes, i know they have a black person in the band).
I think there's more than one (reaching back in my memory I'm remembering the drummer and the horn player).
Virtually all uniquely American contributions to music stem in some way from African American experience. Jazz, Blues, Rock, Hip-Hop. It's all intertwined with black experience. That's inescapable and undebatable.
Claims that sample based work isn't music aren't even really worth discussing. I can't even imagine how someone like Rob or Lazy D would distinguish the "musical complexity" or the level of musical knowledge required of Dave Matthews Band with Girl Talk (entirely sample based) or a DJ like Gramatik.
https://www.youtube.com/watch?v=KH_kPMT9Enw&feature=kp