And as the story goes, his softly-spoken manner was a direct result of his father Joe allegedly forcing him to undergo ‘chemical castration’ when he was just 13 in a bid to delay puberty and keep his singing voice high.
Doctor Conrad Murray – who was convicted of the star’s involuntary manslaughter – claimed Jackson told him he’d been given hormone injections as a teenager, but made him swear never to tell anyone.
Murray, 67, first made the claims in his 2016 self-published book, This Is It! The Secret Lives of Dr Conrad Murray and Michael Jackson.
Michael, third from left, apparently claimed his father Jo, second left, forced him to undergo chemical castration
He wrote: “I often saw Jackson at his most exposed and confessional. He only agreed to share after making me swear, ‘You will never breathe a word. Never.’
“I agreed. I was shocked when Jackson told me. It would explain all of Michael’s unusual behaviour as well as his morphological changes.”
Murray – who served four years for administering the fatal mix of propofol and other sedatives that killed Jackson in June 2009 but maintains his innocence – later branded Joe ‘one of the worst fathers in history’.
However, Jackson’s good friends Liza Minnelli and David Gest once contradicted his account, letting slip that the star had a second, secret voice.
“I think people don’t know the real him. He doesn’t talk like [that],” the David told US chat show host Larry King in 2002.
Like everyone else, Liza believed his high-pitched tone was real and said she got a shock when she picked up the phone one night and heard him talking to husband David in his real voice.
“I said, Michael, you’re busted. I got you now. All these years you’ve been talking that voice,” she recalled.
So what was his ‘real voice’ like? In 2005, Court TV’s Diane Dimond said Jackson actually had a ‘big, deep’ sound.
“Somewhere in there, especially if you bring him bad news or if you make him mad, his voice gets very, very deep,” she told Access Hollywood.
“I was there one day when someone asked him about Gloria Allred, the attorney that has sort of dogged him and turned around in one foul swoop and said ‘She can go to hell’ in this big, deep masculine voice.”
And Good Morning Britain host Piers Morgan corroborated her story, claiming the star once let his secret tones slip during a telephone interview.
He said: “The weirdest thing about Michael Jackson, which encouraged my suspicions about him as a human being, was that when he talked about charity and children he had this very soft, high-pitched voice.
“When I changed the subject to business his voice dropped several octaves and he became a completely different person to talk to.
“That was weird to me, that showed me that he was a different multi-faceted different character depending on the subject matter.”
But why create a fake voice? David and Liza believed Jackson crafted a public persona to protect his inner self after years of ‘hurt’.
“This is who you think I am. And I can be me within these walls. But you can’t come in,” Liza explained.
“He’s been hurt too much, Larry. I mean, things have said kind of rotten things about him. The person that we know is a rather regular guy, believe it or not.”
In his lifetime, Jackson never weighed in on rumours about his voice, but he did repeatedly accuse his father of abuse, claiming the patriarch forced him to strip, covered him in oil and beating him with an iron cord.
“He would just whip you all over your face, your back, everywhere,” he once said, revealing his mother Katherine would plead with him to stop.
He continued: “I would just give up, like there was nothing I could do, you know. And I hated him for it.”