Detroit, MI – A federal judge says Rosa Parks' doctor has to explain why the civil rights figure can't testify in her lawsuit against a rap group. Parks claims the 1998 song "Rosa Parks" by OutKast violated her publicity and trademark rights and defamed her. She also alleges that OutKast and record company BMG exploited her name for commercial purposes. Defense lawyers have asked the 91-year-old Parks to explain the claims that she suffered emotional and mental distress because of the song. At a hearing in Detroit this week, a federal magistrate dropped the individual members of OutKast from the lawsuit, leaving only BMG as a defendant. Parks made history in 1955 when she was arrested for refusing to give up her seat to a white man on a Montgomery city bus.