Michael Jackson was indeed that balding, overweight patient in The Simpson's 1991 'Stark Raving Dad' episode
The Simpsons creator Matt Groening said Jackson voiced the part, but ironically, the singing was done by a "sound-alike singer" and not by the King of Pop
Michael Jackson was believed to have made a cameo in a 1991 episode of 'The Simpsons' as an overweight patient in a psychiatric ward in the episode titled 'Stark Raving Dad.' The '90s kids were curious about the balding character, who boasted a familiar high-pitched voice and could easily carry a tune when singing. The character even claimed to be 'Michael Jackson.' But towards the end of the episode, the character’s voice dropped tremendously, suggesting the whole thing was a ruse.
Fans have speculated all this time, whether it was really the King of Pop in the cameo. Now it has been finally clarified-- by the man who created the Simpson's himself, and that too on day Michael would have been 60.