Carey wore a strapless, green cocktail dress and bling at the neck, ears and wrist, Minaj a short print dress in neutral colors and very bright-pink lipstick.
Urban went casual in jeans and a leather jacket, Jackson wore black atop some shoes that defy my meager powers of description (he later told me, enthusiastically, that they were Prada).
The body language was classic: Minaj mostly kept her legs crossed in the opposite direction of Carey, who crossed hers demurely at the ankles.
And, oh, yeah, they both talked some (though Carey apologized for being a little raspy from a sinus infection).
Asked about the reports of a feud between the two women, Carey said: "The fighting is what it is. This is 'American Idol.' It's bigger than all that. It's bigger than some stupid trumped-up thing."
Asked if each could say something nice about the other (because we do therapy here, too), Minaj replied, "I say nice things about Mariah all the time . . . She's one of my favorite artists of all time. And I think she's really shaped a generation of singers."
When Carey's turn came, she said, "That was obviously a very sweet thing to say," and then observed that the two had worked together once early in Minaj's career and that "I did feel that she was going to go very far."
Fox "reality" chief Mike Darnell later denied that "Idol's" frequent, judge-driven controversies are staged for ratings, or that they overshadow the competition. "There's nothing to talk about but the judges yet, because you don't know the talent," he said.
And speaking of the talent: Don't expect that winning "Idol" will keep your name permanently on the tip of anyone's tongue. After the news conference, a reporter asked Carey how she had reacted when contestants sang one of her songs.
She launched into an anecdote about a winning contestant who'd sung one of her songs and whom she'd mentored on the show.
"David, what's his last name? . . . David . . . ? He sang my song, 'Always Be Your Baby,' and I was mentoring. Blond? I know you know his name - you know who he is. He was great."
Several of us stood there, and, yes, we knew who she was talking about. But at that moment, none of us could remember the full name of Season 7 winner David Cook.
On Twitter: @elgray