The Roots, Anthony Hamilton & The HamilTones, Pentatonix added to NBC's 'Christmas in Rockefeller Center'

'Saturday Night Live's' Alec Baldwin and Kate McKinnon to light Norway spruce tree

The Roots, Anthony Hamilton & the HamilTones and Pentatonix will join NBC's star-studded special "Christmas in Rockefeller Center," set to air live from Rockefeller Center in New York tonight (8-9 p.m. ET/PT). The Roots will perform two songs, one of which will feature Anthony Hamilton & the HamilTones. Two of "SNL's" brightest stars this fall, Alec Baldwin and Kate McKinnon, will be on hand to help light the Christmas tree.

The show will be hosted by "Today" anchors Matt Lauer, Savannah Guthrie, Al Roker and Hoda Kotb, and will also feature previously announced performances from Tony Bennett, Neil Diamond, Josh Groban, Tori Kelly, Sarah McLachlan, Dolly Parton, Jordan Smith, Garth Brooks & Trisha Yearwood and the Radio City Rockettes.

The 84th annual holiday extravaganza will feature a 94-foot-tall, 56-foot-wide Norway spruce from Oneonta. The tree is approximately 90 years old, weighs approximately 14 tons, and will be decorated with more than 50,000 multicolored LED lights.

For the eighth consecutive year, "Green Is Universal" - NBCUniversal's sustainability initiative in partnership with the Arbor Day Foundation - will kick off its annual tree-planting campaign during the "Christmas in Rockefeller Center" broadcast. This year viewers can "Share a Tree" to a national forest, by using #ShareATree or visiting www.greenisuniversal.com to create and share an animated holiday story. Each action will contribute to the Arbor Day Foundation's tree-planting efforts, funded by a $25,000 donation from NBCUniversal.