Kelly Clarkson will host the 91st celebration this year, which marks 20 years since her first “Christmas ... and Colombian singer Manuel Turizo will also appear at the tree lighting.

And, the Rockefeller Center Christmas tree has been put up ... Carly Pearce and Manuel Turizo. Blackstone and Palmer, Foster and McPhee, and Gillies and MacFarlane will perform holiday duets.

This week, it's time for the final big milestone to mark the start of the holiday season -- the Rockefeller Center Christmas Tree Lighting ... Carly Pearce, and Manuel Turizo.

Carly Pearce and Manuel Turizo. The Rockettes will also perform a number from their "Christmas Spectacular." Rockefeller Center's first Christmas tree lighting officially took place in 1933 ...

Heading to Rockefeller Center for the tree lighting on ... Carly Pearce, and Manuel Turizo. The Radio City Rockettes will also perform a number from their "Christmas Spectacular." ...