Christmas in Rockefeller Center is a holiday tradition for NBC, with musical guests galore turning up for the lighting of the world’s most famous Christmas tree. Yet the 81st annual celebration might be the most star-studded lineup yet.

It’s not just about the music, however, as the ceremony will culminate in the lighting of a 76-foot Norway Spruce that is 47 feet in diameter and weighs approximately 12 tons. The tree, estimated to be about 75 years old, will feature more than 45,000 energy-efficient multi-colored LED lights, and will be topped with a 9 ½ foot wide LED-lit Swarovski crystal star.

The lighting of the tree is a tradition that dates back to 1933, in the midst of the Great Depression. The inaugural Rockefeller Christmas tree was decked with a comparatively scant 700 lights and placed in front of the then eight-month-old RCA Building, which is currently the GE Building. The annual event became a spectacle in 1936 with the opening of the Rockefeller Plaza outdoor ice-skating pond, yet it wasn’t until NBC-TV televised the tree lighting for the first time in 1951 on The Kate Smith Show — and as part of the nationwide Howdy Doody television show from 1953-55 — that the ceremony became iconic.