An old stereo player which Eminem learned how to rap on is being sold by his grandmother for $5,000 (GBP2,860). BETTY KRESIN says the young Eminem - real name MARSHALL MATHERS III - would sing over music on the boom box belonging to his uncle. Kresin, 64, from Kansas City, Missouri, says, "Ronnie had this stereo in his bedroom and him and Marshall would go up there and crank this thing up. "They would play records and start rapping over the music and tape it. "In the summer, when the windows were open, the neighbours would go crazy. But Marshall didn't care."