U.S. President Barack Obama (R) sings a song with Santa Clause during the National Christmas Tree Lighting ceremony on the Ellipse before the White House in Washington D.C., capital of the United States, Dec. 1, 2011. The lighting of the National Christmas Tree has been a celebration of the holiday season since 1923. The lighting of the newest National Christmas Tree measuring approximately 26 feet, includes about 65 sets of proprammable multi-colored LED lights and 160 starburst ornaments, with a total wattage under 2000 watts. [Xinhua/Zhang Jun]