It's the most wonderful time of the year! Mariah Carey, who also performed in both 2010 and 2012, was chosen as a headliner for this year's Christmas tree lighting ceremony at Rockefeller Center in New York City. For the pre-taping of the performance, the singer got into the holiday sprit, wearing two very festive dresses that wowed everyone in the audience.

The holiday classic "All I Want For Christmas Is You" singer flaunted her ample cleavage and curvy figure for both of her performances. She first graced the stage in a red sweetheart-cut body-hugging strapless gown. Carey completed her Christmas/Santa ensemble with a white furry shawl and pair of black opera gloves that almost came up to her shoulders. She had a sparkling microphone and stand to match the diamentés on her dress, diamond bracelet and dramatic jeweled earrings.

As the cameras rolled during her performance, the 43-year-old singer sang in front of a group of young dancers dressed as elves, while a choir stood behind them, acting out as her backup singers.

Mariah Carey later changed into a white fishtail strapless gown, which also accentuated her curves. The dress featured a plunging neckline and was detailed with silver beading, and the singer matched the gorgeous gown with a pair of white opera gloves.

Carey also shared her wardrobe choices via Instagram. "I know it's a lil' over the top lol #rockefellercenter #Christmastreelight," she captioned the image.

The 75-year-old tree, 76-foot Norway Spruce from Shelton, CT is set to be lit by 45,000 multi-colored LED lights and topped with a 9 ½ foot-wide Swarovski star.

Kelly Clarkson, Mary J. Blige, Ariana Grande, Goo Goo Dolls, Jewel, Toni Braxton and Babyface will be joining Mariah Carey for the holiday celebration, as well.

The 81st annual Rockefeller Center Christmas tree lighting will air today in full on NBC at 8 p.m. EST.