Singers Stevie Wonder and Mariah Carey are among a bevy of stars slated to appear at Michael Jackson's memorial service, organizers said Monday. Soul legend Wonder and pop diva Carey were included on a provisional list of participants at Tuesday's ceremony which will also include stars such as John Mayer, Lionel Richie, Smokey Robinson and Usher. Other celebrities taking part at the Staples Center include Jackson's former girlfriend Brooke Shields, Los Angeles Lakers star Kobe Bryant and Oscar-winning actress and singer Jennifer Hudson.