Seth MacFarlane at the Grove in Los Angeles (Neon Tommy/Shea Lenniger).

With special performances by The Beverly Belles trio, “Dancing With The Stars” alum, and Trainor, those in attendance welcomed the holiday season to Los Angeles. 

Here's six of the evening's top moments that prove the holidays have arrived to sunny Los Angeles.

1. Celebrities Discuss What Starts the Holiday Season

The stars arrived on the red carpet decked in holiday outfits. When asked to finish the sentence, “It’s not the holiday season until…” here are their responses:

“You’ve got turkey and stuffing.” -Katharine McPhee.

“That tree is in my entryway.” -Molly Sims.

“You light some candles and get around your family.” -Meghan Trainor.

Sarah Hyland and Meghan Trainor pose with Santa Claus (Neon Tommy/Shea Lenniger).

Other special guests included Los Angeles Mayor Eric Garcetti and, of course, Santa Claus.

They took a break from the holiday chat to briefly address their thoughts on the recent terrorist attacks in Paris, France. After discussing how spectacular this event is every year, Mayor Garcetti added, “Especially after what happened last night, too, it’s important for us to get out, to be free, and to hug your loved ones a little bit closer tonight, that’s why I’m here.”

Similarly, Santa gave a suggestion on how we can all make a tribute to Paris and show our support. “One of the beautiful things I saw today, of course, was the Eiffel tower and the lights were on, but all the other cities around the world turned their lights on, too. Turn a light on for the people of Paris. That’s one thing you can do.”

Meghan Trainor and Santa Claus (Neon Tommy/Shea Lenniger).

Once the show started, MacFarlane didn’t fail to bring his humor onstage. He snuck in jokes between his songs, including a nudge at Californians and their “gluten-free hot cocoa and cruelty-free marshmallows.” His spot-on impersonation of a Liam Neeson-esque Santa threatened, “I will find you, and I will bring you socks for Christmas,” which elicited a roar of laughter from the audience. 

4. Performances by Meghan Trainor and Katharine McPhee

Backed by a 70-piece orchestra, MacFarlane dazzled with his sultry vocals on Christmas favorites and was later joined by Meghan Trainor for a duet of Bing Crosby’s “Little Jack Frost Get Lost.” Trainor then grabbed her ukulele and covered Justin Bieber’s “Mistletoe” with a reggae feel that the crowd loved. It was a fun twist that even MacFarlane said he enjoyed.

Finally, McPhee joined him onstage for a playful rendition of “Marshmallow World." McPhee covered a beautiful version of “What Are You Doing New Year’s Eve?” and dazzled the audience with her powerful voice. All of these performances made you want to hold your loved ones close, find some mistletoe, grab some hot cocoa and celebrate the start of the holiday season.

The Grove invokes holiday spirit (Neon Tommy/Shea Lenniger).

MacFarlane finished off his set with a unique take on “White Christmas.” As he began the song, an excited gasp escaped from the audience as “snow” fell around the stage. It was a magical feeling as Los Angelenos experienced their version of a white christmas while being serenaded by MacFarlane. Suddenly, he took the seriousness for a turn and began singing in voices of favorite characters from his show “Family Guy.” How many people can say they’ve heard Stewie sing “White Christmas”?

6. Santa, Fireworks and the Tree Lighting

Of course, what’s the holiday season without Santa, fireworks and some lights? Once MacFarlane wrapped up his last song, Santa jumped out from behind the curtain to welcome everyone and count down to the tree lighting.

The Grove was filled with the sound of the audience counting down and finally fireworks exploded into the sky. The 100-ft tree lit up and Santa welcomed the holiday season with a classic: “Ho, ho, ho, Merry Christmas!”

Break out your decorations, kiss under the mistletoe, heat some hot cocoa and bake holiday cookies, because the holiday season has officially started in Los Angeles!

Reach Staff Reporter Shea Lenniger here.