Star-struck singers, rappers and actors, including Barbra Streisand, Kanye West and Miley Cyrus, checked their egos at the door to record a new version of "We Are The World" for Haiti earthquake victims, 25 years after the song raised awareness of the famine in Africa.
None of the singers of the original song were invited to participate in the update, which was recorded at the same Hollywood studio once again under the oversight of Quincy Jones and the song's co-writer Lionel Richie.
In all, more than 70 stars lent their voices to the song, and they all seemed in awe of each other.
"As celebrities, we're fans of one another, so we're all looky-looing in there, and getting autographs and numbers," said Natalie Cole.
Streisand, Celine Dion and Tony Bennett appeared to inspire the most stares. Fifteen-year-old Canadian heartthrob Justin Bieber, who sang the opening line originally performed by Richie, joked that he would ask his new friend, R&B singer Akon, to get the telephone number of Nicole Scherzinger of the Pussycat Dolls.
Streisand, a noted perfectionist, ran through multiple takes of the line originally sung by Diana Ross, each one seemingly better than the previous one. Jazz singer Patti Austin came into her recording booth to coach her.
Guitar virtuoso Carlos Santana sang along, even though he is not a singer. Two members of the Beach Boys, Brian Wilson and Al Jardine, appeared to ignore each other.
Classical crossover tenor Josh Groban described the event as "inspired chaos."
"Everybody left their ego at the door," he said, referring to a sign that Jones hung in the studio during the original session on the old A&M Records lot on January 28, 1985.
"To be smack-dab in the middle of a sandwich between Barbra Streisand and Weezy [rapper Lil Wayne] was personally a creative experience I don't think I'll ever have the pleasure of having again," Groban added.
For his part, Lil Wayne said his mother asked him to get a photo of Gladys Knight.
He was among a heavy quotient of hip-hop stars, including Snoop Dogg, Lil Wayne, Drake, LL Cool J, and will.i.am of the Black Eyed Peas as well as West.
"Hip-hop is rock 'n' roll to a lot of people around the world, right now," said Jones, explaining the absence of the modern-day equivalents of original performers Bruce Springsteen, Bob Dylan or Paul Simon.
Lil Wayne, for one, said he was not a singer, and thought organizers were joking when they asked him to perform the line originally sung by Dylan. Asked if he did a better job, Lil Wayne said, "Hell no!"
But the rapper added a note of discontent: "It's amazing what's being done for Haiti, but it's amazing what hasn't been done for New Orleans" (after Hurricane Katrina in 2005).
A few of the original lyrics, which Richie wrote with Michael Jackson, have been updated, and will.i.am contributed some raps. Jackson's sister Janet Jackson, who was not present at the session, was scheduled to sing his lines from a studio in Atlanta on Tuesday.
Country and Latino artists were notably under-represented. Organizers said they were turned down for various reasons by some stars. In fact, most of the big Grammy winners from the night before were absent, including Beyonce and Jay-Z, who returned to New York, and Taylor Swift, who flew to Australia straight after the ceremony.
Randy Phillips, one of the organizers, said his "one regret" was the absence of dance-pop star Lady Gaga.
The song, which was still being worked on into the small hours of Tuesday, will make its world premiere during NBC's coverage of the Vancouver Winter Olympics on Feb. 12.
Both the song and an accompanying video, shot by Oscar-winning "Crash" director Paul Haggis, will go on sale both through traditional and online retailers.
Phillips said all proceeds will go to a newly established foundation that will carefully monitor disbursement.
The Jan. 12 earthquake killed up to 200,000 people in Haiti and devastated the already impoverished nation.