Mario Lopez served as the host for iHeartRadio's Holiday Special, which saw performances from the likes of Kelly Clarkson, Michael Bublé, Pentatonix, and Train.

Kelly Clarkson opened up the show with a performance of her song "Christmas Isn't Canceled (Just You)," from her recent holiday album, When Christmas Comes Around.... Michael Bublé then followed up with a cover of "It's Beginning To Look A Lot Like Christmas," getting into a classic holiday spirit.

Clarkson went into what inspired her to write another Christmas album, sharing she had written it "by happenstance." "My label, we were talking about making a couple songs because I wasn't done with my like, normal album yet, and I wasn't really ready to put it out," Clarkson said. "So we ended up making this, a whole Christmas album, which is kinda funny because I wasn't feeling very cheerful. But, the album ended up being very theraputic for me. There's a lot of differnt kinds of emotions going on with the whole album, and it's not just all one thing. I feel like Wrapped in Red, I loved that Christmas record, it's one of my favorite records I've ever done, it is more like one feeling. And this record has just, a lot more depth to it. And just a little bit of sadness in it. Sometimes, when Christmas comes around, you're not happy. And that can be okay."

The Pentatonix followed up with a performance of "I Just Called To Say I Love You" and "I Saw Three Ships." Train then played one of their favorite Christmas songs, "The River." Joined by a simple piano, the soft harmonies created a magical spirit as they sat in the midst of a forest of Christmas Trees. "The River" was followed up by "this Christmas."