*Diana Ross will join “The X Factor” judge Demi Lovato and “Gangnam Style” sensation Psy to headline the annual Christmas in Washington special airing Dec. 21 on TNT.

President Barack Obama and First Lady Michelle will attend, and TNT’s late night host Conan O’Brien will host the telecast, to be taped in Washington D.C.’s National Building Museum, for the second consecutive year.

Additional performers include “Smash” star Megan Hilty, former “The Voice” finalist Chris Mann and “American Idol” winner Scotty McCreery.

This is the 14th year TNT will be broadcasting “Christmas in Washington.”