The cast boasts Oscar, Golden Globe, Emmy and Tony winners -- and a group of up-and-comers that's a veritable Who's Who of young Hollywood -- but it was for the producer of the flick that traffic stopped last night outside the Egyptian Theatre in Los Angeles, where [movie id="379404"]"Cadillac Records"[/movie] held its world premiere.

OK, it doesn't hurt when you're a producer that also stars in the film -- and it really doesn't hurt when your name is [artist id="3117360"]Beyoncé Knowles[/artist].

But if she was the highlight of a red carpet which also included co-stars Jeffrey Wright, Columbus Short, Adrien Brody and Gabrielle Union, chances are [artist id="3117360"]Beyoncé[/artist] didn't see it that way -- which was exactly what made her so much fun to work with in the first place.

"Beyoncé came to get down, like everyone else did. She came in with no ego," Wright beamed of Mrs. Carter to MTV News. "She just was so willing to let it out and be vulnerable and emotionally present. We were all part of an ensemble that came to smoke -- that came to celebrate that music."

"I think she really did the work, and it shows," added Short. "She deserves kudos for it. She deserves a round of applause."

She'll likely get much, much more -- already being pegged as a possible Oscar nominee for her performance as [artist id="450150"]Etta James[/artist], a role for which she reportedly [article id="1597575"]gained 15 pounds[/article].

As Short [article id="1582527"]explained to MTV News last February[/article], the film follows the flood of musicians who populated and made famous the hallowed halls of Chess Records, where singers like Chuck Berry (Mos Def), Muddy Waters (Wright) and, yes, Miss James got their start.

But while the many who walked the carpet couldn't hold back their praise for her, the 27-year-old superstar told MTV she was waiting for the good news from just one more spectator before she could call it a day.

Luckily for her, that one person -- Etta James herself -- was in attendance.

"She is! Just imagine!" a nervous Beyoncé squealed, half in delight, half in fear. "She's one of my heroes, and I always loved her voice, but now knowing what she's been through, she's one of my heroes. I'm not sure if she thought [I would be good] as her. I'm very, very nervous.

And now?

"I actually spoke with her and she told me, 'I loved you from the first time you sung,' " Beyoncé beamed.

Judging from the fans who dotted the red carpet for a glimpse of their favorite chanteuse, that makes Etta James just like the rest of us.

[movie id="379404"]"Cadillac Records"[/movie] opens December 5.

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