This is not meant to be racist, but in Jazz music, I am not a fan, don't get me wrong, the Jazz Musicians are amongst the best, but at times it is just so boring. but in to Pop music then the best singers are white.
Look at Jo Stafford, she could sing anything and was much more versatile and better than any black female singer.
Now tell me any better black singers or white for that matter, than Elvis, Roy Orbison or Gene Pitney.
Jo Stafford was probably the best female singer ever, I never heard her in her heyday, but have sure heard a lot of her since.