Rok, when comparing Mary Lou, and Dorothy, you are side stepping a social issue that affected "all" African American artists at that time; they had to be "entertainers", even if they were serious musicians. This gave us "Mantan Moreland" and "Stepin Fetchit". In no way am I bringing Dorothy down to that level, I'm just expediting the discussion.
Mary Lou never wavered in regard to whether or not she was a serious musician, and not an entertainer. Although Dorothy was as good a musician as Mary Lou, her standard of living, or should I say "making a living", was of a higher priority and she "entertained". No, I'm not bringing Dorothy down, I'm simply shining a light on the circumstances African Americans were confronted with in this country at that time. Do you care to address this? If not, I'll understand.
Enjoy the music.