2Pac’s The Don Killuminati: The 7 Day Theory, released just two months after his September 1996 murder under the alias Makaveli, wasn’t a star-studded affair like his previous album, All Eyez On Me.

Where All Eyez On Me boasted blockbuster collaborations with the likes of Dr. Dre, Snoop Dogg, Method Man, DJ Quik and George Clinton, Makaveli featured mostly R&B singers and members of ‘Pac’s group, the Outlawz, with production coming from lesser-known names from Death Row’s “wack room” at Can-Am Studios.

However, the album almost featured an A-list collaboration that would’ve gone down in the history books.

In BET’s oral history of The Don Killuminati: The 7 Day Theory published earlier this month to coincide with what would’ve been 2Pac’s 51st birthday, Quincy “QD3” Jones III — the son of the legendary Quincy Jones and producer of “To Live & Die in L.A.” — revealed ‘Pac’s camp reached out to Michael Jackson in hopes of featuring him on “Thug Nature,” which was originally intended for the album.

However, the King of Pop turned down the request for one simple reason: out of loyalty to ‘Pac’s rival, The Notorious B.I.G., who he worked with on “This Time Around” the year before.

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“So I set up a meeting at Neverland [Ranch],” said QD3, who worked with director Allen Hughes on the upcoming FX docuseries Dear Mama, which examines ‘Pac’s relationship with his Black Panther mother Afeni. “I go up there and told Michael about it. And do you know what Micheal said? He liked Biggie.”

“Thug Nature,” which samples Jackson’s 1983 Thriller hit “Human Nature,” didn’t end up making the album. It eventually wound up on the 2000 Death Row compilation Too Gangsta For Radio, as well as various posthumous 2Pac projects.

QD3, who also produced All Eyez On Me‘s “Heaven Ain’t Hard 2 Find,” delved deeper into his experience working with Tupac Shakur during his chat with BET.

“‘Pac would take all my beats including the ones I would never play for people,” he said. “I learned a lesson that you gotta be spontaneous more and he taught me how to just think and just do it. ‘Pac would get irritated when you sat there and fiddled with sounds almost like you were disrespecting his time a little bit.”

He added, “I would say he was manic. There would be moments that called for quiet voice and candles and all that and he would be screaming and smoking Newports. He was on fire with this manic push. He was always pushing. You could tell he wasn’t comfortable in some way and there was something that was making him uncomfortable.”

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Despite missing out on a Michael Jackson collaboration, The Don Killuminati: The 7 Day Theory remains one of 2Pac’s biggest albums. The project debuted at No. 1 on the Billboard 200 after selling over 660,000 copies in its first-week and has since been certified quadruple platinum.

It also remains his most intriguing. The crucifixion cover art and Makaveli moniker — a nod to the 16th century Italian philosopher Niccolo Machiavelli who was believed to have faked his own death to fool his enemies — continues to fuel conspiracy theories about his supposed whereabouts.

As for Michael Jackson, the late King of Pop has posthumously worked with a select number of rappers since his death in 2009, including 50 Cent (“Monster”) and Drake (“Don’t Matter To Me”).