Jennifer Lawrence appeared on Late Show With David Letterman last night, and the 24-year old actress looked absolutely stunning, but she revealed that there's one thing she can't do: sing!

"I do not like singing in front of other people, that's like, my biggest fear," J. Law told Letterman. "I cried on set that day ... That was awful -- I'm scarred from my childhood. I have a Southern mother that used to tell me I was amazing at everything and I could do everything, but I can't. I had this tone-deaf-Amy-Winehouse rahhh voice and I sang in front of the school when I was 8, because I thought I could ... My dad laughed for the entire week! I'd hear him around the house, imitating me. I hate it, I hate it!"

But she can't really be that bad, because producers included a clip of the Oscar winner singing in The Hunger Games: Mockingjay - Part 1, which hits theaters on Friday. Chris Martin's on-again/off again girlfriend says she still hasn't heard her audio though. "I was like, will you guys please get Lorde and lip-sync it?" she joked. She also sang in the first Hunger Games flick, but her voice was barely projected above a whisper, so we couldn't tell just how tone deaf she was...

But really, the absolute best part of the interview is when J. Law and Dave sing a Cookie Monster-esque version of "Holly Jolly Christmas" -- check out the video above!

After taping her appearance, however, thing got a bit chaotic outside of the studio when a number of fans actually pushed over a metal barrier when the actress was signing autographs. Luckily security whisked J. Law away and it doesn't appear as though anyone got hurt, but dayum! It sounded like a scene straight outta Panem...