Lady Gaga and Tony Bennett sing 'It Don't Mean a Thing (If It Ain't Got That Swing)' (VIDEO)

Lady Gaga and Tony Bennett sang 'It Don't Mean a Thing (If It Ain't Got That Swing)' on Christmas in Rockefeller Center on Wednesday, December 3, 2014.

Lady looks great in her white outfit. Very classy.

Tony Bennett is one of Gaga's favorite collaborators and it's very nice that they are sharing the holiday spirit this year together.

Their album Cheek to Cheek is out now. And the duo are going out on tour in 2015. Check out the tour dates.

The annual special for the tree lighting in New York on NBC was hosted by Matt Lauer, Savannah Guthrie and Al Roker.

Watch the video here: