being a "(insert) Madonna" means you re invent yourself.
Rihanna has re invented herself more then Beyonce.
Beyonce has a secret formula that works amazingly every time and its called "Slay".
But ya Rihanna is the black Madonna.
EDIT:
Why do we need to compare them to another successful woman stawwwp OP just staaawwwppp it your hurting all of us. boohoo.
