On his second album "The Marshall Mathers LP," Em performed this chilling little ditty about domestic violence and obsessive fans with pop star Dido. For the 2001 Grammys, he enlisted one of the biggest names in music to tickle the ivories and sing the hook: Sir Elton John. At the time, GLAAD and other groups condemned John's decision to perform with the rapper due to his homophobic lyrics, but the performance itself  is mesmerizing.

http://www.youtube.com/watch?v=ZY2p7oE7Bpw