Redefining diva

"Sheryl Lee Ralph's superstar performance as the original Deena in Broadway's groundbreaking musical Dreamgirls didn't happen overnight. First came a grueling Hollywood apprenticeship, where roles for young black women at the time were often offensive and demeaning. Sherly Lee, however, held stubbornly to the values of her mother and grandmother: she wouldn't take any part she couldn't be proud of. Even after joining Dreamgirls -- where she helped create a role that grew from her own life story -- she would invest years of sweat and tears before the play finally opened to instant acclaim. In…