"Check your egos at the door."

If anyone in the music business of the '80s had enough clout – and a big enough ego of his own – to use that message as a greeting for the world's biggest pop and rock stars, it was producer Quincy Jones. Tasked with corralling an incredible array of famous voices for the all-star charity single "We Are the World," Jones offered each of his participants a stern reminder that the cause they were supporting was bigger than any of them.

Sparked by an idea from singer and social activist Harry Belafonte, Jones was instrumental in bringing "We Are the World" to life – right down to figuring out who should write the song. Brought into the process after Belafonte had connected with manager Ken Kragen, who enlisted his clients Lionel Richie and Kenny Rogers and secured the participation of Stevie Wonder, Jones quickly reached out to Michael Jackson, who eagerly agreed to co-write with Richie and Wonder. After Wonder begged off due to time constraints, the composing trio was down to a duo.

"Quincy walks in the door and says, 'I need the song now,'" Richie recalled years later. "And a day later, we had the bones for 'We Are the World.'"

Richie was guilty of overstating the speed of their writing process a bit – it actually took a few days – but the urgency of their mission was real. Conceived as a way of helping collect money and food for the million-plus victims of Ethiopia's ongoing famine, Belafonte's brainchild grew in scope, ultimately becoming an organization dubbed United Support of Artists for Africa (USA for Africa for short).

Spurred on by the group of all-stars that Bob Geldof had previously assembled for his own Band Aid recording, Jones and his fellow organizers put together a Who's Who of pop and rock in 1985, lining up a series of new and previously unreleased recordings from Steve Perry, Bruce Springsteen, Chicago, Huey Lewis and others – all while scheduling a celebrity-studded session that would bring some of the biggest names in the business together in one studio.

The recording took place on Jan. 28, 1985, at the A&M Studios in Hollywood. Drifting in after the American Music Awards ceremony held earlier in the evening, the "We Are the World" cast took its spots; by 10:30, they all stood side by side, an eyebrow-raising assemblage that included an incredible list of soloists (Perry, Springsteen and Lewis among them) as well as an eclectic chorus that boasted everyone from Dan Aykroyd to Bette Midler and Lindsey Buckingham. For some of the participants, the spectacle was just as surreal as it would have been for anyone off the street.

"When I finally got there, I had a jacket on – an Italian general's jacket with tails – and I see Michael's [Jackson] jacket and I said, 'Oh, no!,'" Cyndi Lauper told Interview. "So I took it off, also because I had mousse on that was flaking all over the jacket, so it looked like I had yellow dandruff. I was standing next to Billy Joel, who was gracious, and Bruce Springsteen."

For Jones, who'd already done a ton of legwork shepherding the songwriting and recruiting participants by mailing out a series of numbered cassettes with notes imploring the artists not to share or discuss the project, the delicate task of blending all these celebrities into a coherent song was finally truly under way. Again, if anyone had the chops, it was the man often referred to simply as "Q."

"Quincy was the best at that because he's Mr. Personality," laughed Richie. "He knows how to let things float for a minute, then reel it back in. So, you know, one line, that's Paul Simon. One line, that's Tina Turner. So, of course, the ultimate question came down, 'Lionel, when would you like to come in?' I said, 'First.' I’m not crazy."

Watch USA for Africa Perform 'We Are the World'

One of the more recognizable voices belonged to Bob Dylan, who famously turned to Wonder for a bit of impromptu vocal coaching – and who later told the ABC news program 20/20 that he participated even though he had a few mild misgivings about the effort in general.

"People buying a song and the money going to starving people in Africa is, you know, a worthwhile idea, but I wasn’t so convinced about the message of the song, to tell you the truth," shrugged Dylan. "I don’t think people can save themselves, y’know."

Dylan wasn't the only one who had second thoughts. Prince was enjoying a career year, and plans at one point called for him to trade vocal lines with Jackson on the track, but he ultimately decided not to show up for the session – reportedly because he was annoyed that he wouldn't be able to play guitar on the song – and suffered PR blowback even though he contributed a song, "4 the Tears in Your Eyes," to a charity album that was released in April.

Regardless of who passed on the chance to participate, "We Are the World" – and the USA for Africa album – was a historic success, topping the charts and selling millions around the globe while drumming up sorely needed food and funds. For fans, it offered a unique opportunity to see and hear some of their favorite artists in one place; for idealists in and outside the organization, it offered resounding proof that art could be used in service of the greater good. For those who were there, it provided a career milestone that many would never forget.

"It was an amazing night. Imagine meeting all those people," Lewis told the A.V. Club in 2012. "Most people don’t meet those people in their career. Just to all be there in the same room, it was fantastic. I got to hang out with Springsteen a little bit. I haven’t seen Bruce Springsteen in, s---, 10 years probably. But I know that we’re pals, in a way, because of that. We shared that experience together."

"Do They Know It's Christmas" and "We Are the World" arrived at a particularly socially active moment for pop and rock music, springing to life alongside like-minded events such as the Live Aid, Farm Aid and Amnesty International concerts. At a certain point, celebrity fundraising overkill started to set in, and it became fashionable to be cynical about music's ability to make a difference – Jones himself later admitted that despite their best efforts, there was a depressing amount of waste in the way USA for Africa's initial windfall was distributed. But for anyone who remembers the single's release, it's impossible to deny the air of excitement that surrounded "We Are the World."

"You know, when you start something like this, you don't know what's going to happen – you never do," Jones told the Today Show in 2005. "One by one as they came in, they started to see each other, and they couldn't believe it. When I think about that night, I get goosebumps."