The singer had actually voiced a character on the show.
Matt Groening has finally confirmed that Michael Jackson had collaborated with him on The Simpsons for an episode called "Stark Raving Dad." Fans have been speculating about the singer's appearance on the show since it aired in 1991.
Many had attributed the voice that gave life to one of the mental health patient characters to Jackson, but this idea was only a theory until now. The show's creator demystified the situation during an interview with The Weekly, an Australian program: "We really did have him."
Jackson's voice was also a source of confusion for Groening before they met. When he received a phone call from the pop star regarding the possibility of his participating in the show, the producer thought he was being prank called.
"He has the voice of someone doing a Michael Jackson bit."
One of the main reasons why fans have been debating about the episode in regards to Michael's voice is the omission of his name in the credits. The deal wasn't exactly conventional either. Michael Jackson only voiced the character when he spoke, but another entertainer took care of the scenes in which the character sang.
"He did the show, he didn't want credit for it — it was some kind of deal with his record company or whatever. So when it came time to sing the songs, he had a soundalike singer. And he stood there and watched the guy who was so nervous, who had to sound like Michael Jackson,"