5 most recognizable voices in American music?

While watching CNNs Larry King interview Johnny Cash a few days ago, I commented to my wife that Johnny Cash probably has one of the five most recognizable voices in American music today. My wife agreed and then asked "Well who are the other four?" After some discussion, we came up with our nominations (in no particular order):

Johnny Cash
Elvis Presley
Ray Charles
Barbra Streisand
Louie Armstrong

This question probably assumes that the singer is quite famous and that their music has been around quite awhile-- or they became really famous really fast. We'd be interested in knowing what other A'Gon members think about these five, or others you would nominate instead for this "top five"? Thanks. Craig