Why Prince and Madonna didn’t join Michael Jackson for ‘We Are the World’: doc

“We Are the World” was one a once-in-a-generation meeting of musical giants when it was recorded on Jan. 28, 1985 — and released two months later on March 7 — to benefit African famine relief.

Anyone who was anyone in music at that moment — a who’s who of legends including everyone from Stevie Wonder, Diana Ross and Bob Dylan to Billy Joel, Tina Turner and Bruce Springsteen — showed up to support the cause.

Written by Michael Jackson and Lionel Richie and produced by Quincy Jones and ’80s hitmaker Michael Omaritan, the single sold a whopping 20 million copies.

But two ’80s pop royals — Prince and Madonna, the Queen of Pop — were missing from the megawatt mix on that star-studded night at A&M Recording Studios in Hollywood, right after the American Music Awards.

The new documentary “The Greatest Night in Pop” — which premiered at the Sundance Film Festival on Friday and will begin streaming on Netflix on Monday — reveals why the two ’80s icons didn’t participate in the historic recording.

Prince — who was rumored to be in a feud with Jackson for pop supremacy after his 1984 “Purple Rain” blockbuster — was actually courted by Sheila E., his singer-drummer protegée Sheila E., who was invited by Richie to the all-star session in hopes that she would convince her enigmatic mentor to participate.

“Man, you should come — it’s really cool,” she told Prince, who was chilling at the Mexican restaurant Carlos ’n Charlie’s after taking home three trophies and performing “Purple Rain” at the AMAs.

But Prince would only come if he could record a guitar solo in room all by his regal self.

“I knew he wasn’t going to come because there were too many people,” says Sheila E. in the documentary.

So, instead, Huey Lewis — of Huey Lewis and the News fame — sang the part that was meant for Prince.

But at least Prince was invited. That wasn’t the case for Madonna.

Still at the beginning of her game-changing career — after releasing her 1983 self-titled debut and 1984’s blockbuster “Like a Virgin” — the Material Girl was passed over in favor of Cyndi Lauper, who was riding high on the success of her 1983 debut “She’s So Unusual,” featuring the smash “Girls Just Want to  Have Fun.”

And that was all because of Ken Kragen, Richie’s then manager, who was the initial mastermind behind “We Are the World.”

In the doc, Kragen’s then associate Harriet Sternberg reveals, “I wanted Madonna, but Ken wanted Cyndi.”