<P> The season four episode "If I Should Die Before I Wake" dealt with the AIDS epidemic . It featured actress Tisha Campbell - Martin as Hillman student Josie, who reveals during a class project that she has contracted the disease from a former boyfriend and would probably die shortly after graduating college . Because of the reveal, some of the students (including Gina and Terrance) start to treat Josie as an outcast by either covering their face around her, or refusing to have her serve food at the Pit . Their attitudes towards Josie change after being chastised by Kim and Mr. Gaines . The dialogue also causes Whitley (who was still a virgin) to put off a sexual relationship with Dwayne . Whoopi Goldberg stars as the professor who conducts the class . </P> <P> As a show developed by Bill Cosby for a character from The Cosby Show, A Different World had many connections to its parent program, even before the latter program was created . The third season finale of The Cosby Show, entitled "Hillman", was essentially a pilot episode for the new show . </P> <P> The theme song was co-written by Stu Gardner, Bill Cosby, and Dawnn Lewis--who was also a cast member . In the online interviews related to the 2006 "Hillman College Reunion," Lewis revealed that her being approached to write the song and to audition were two separate events that occurred within a short time of each other, such that she thought it was a practical joke by her friends . The song was performed by Phoebe Snow in season one, then by Aretha Franklin in seasons two through five, and Boyz II Men in season six . </P> <P> The spin - off program featured many appearances by characters from the parent program, especially in the initial season, in which Denise's father Cliff (Bill Cosby), mother Clair (Phylicia Rashad), younger sisters Vanessa (Tempestt Bledsoe) and Rudy, brother Theo (Malcolm - Jamal Warner), and grandfather Russell (Earle Hyman) all appeared on the show, either at Hillman or at the other end of a phone call . Denise's departure from Hillman after Season 1 did not stop her mother from reappearing on the show . Three of Phylicia Rashad's four appearances as Hillman alumna Clair Huxtable took place after season one, and in one of these, she brought her younger daughter Vanessa to tour the college . Sondra was the only Huxtable child not to appear on the show . Martin (Joseph C. Phillips) and Olivia (Raven Symone) appear in season 3 episode "Forever Hold Your Peace" along with Phylicia Rashad and Lisa Bonet . Elvin (Geoffrey Owens) and Pam (Erika Alexander) also never appeared on the show . </P>

Who sang the theme song for it's a different world