Sia Premieres Her Annie Song

Earlier this morning, Sia called into the Elvis Duran and the Z100 Morning Show to premiere her new version of Annie's classic "You're Never Fully Dressed Without a Smile," which will be played across the nation when Jay-Z and Will Smith's Annie remake hits theaters later this December.

When asked about Annie, Sia said: "It was my favorite musical growing up; I must've watched it about 150 times!"

Her fans will be excited to hear that she's even got a speaking part in the movie. It was supposed to be larger, but she ended up opting for a smaller, more comfortable role, "Even just talking about it gives me such a sick feeling, I'm such a bad actor! But yes, I do two lines. What's terrifying is actually, originally, I was supposed to play the role of the social worker ... Thank god I didn't get it, because it just would've been the most humiliating experience of my life!"

When the singer, who has refused to be photographed since her newfound popularity and huge hits, was told she was a top Halloween costume choice this year, she took it in stride:

"This is so exciting! Someone told me they heard on the radio yesterday that it could be the number Halloween costume this year and this is my dream! When I created the blonde bob brand, the idea of just anyone can be this singer. I was like little kids could do this! It will be like 5 bucks for a wig, 5 bucks for a unitard, that's an affordable Halloween costume; I think we should do it! I'm so excited!"

Annie premieres in theaters December 19 later this year. Watch the video for the new song below: