After release her latest single “Imagine” last week, Ariana Grande stopped by The Tonight Show to perform its TV debut.

Grande’s performance of her new track is stunning. When she reaches the high notes toward the end of the song, which some fans first mistook as whistling sounds, the audience bursts into reactionary cheers. She sings while sporting her classic “lampshade” look—wearing a big Christmas sweater and thigh high boots. At the end of the performance, Jimmy Fallon gives an exasperated, “are you kidding me?!”

No doubt one of the reasons people are so excited to see Grande’s live performance of her new single is the back story. It’s universally agreed that “Imagine” is an ode to the late Mac Miller. It’s a dreamy but crestfallen track that allows Grande and her audience to dwell in what could have been.

Miller died of an accidental overdose in September, affecting Ariana in a number of private and public ways. In her own words on Twitter, the singer wrote that “Imagine” is about "pretending it never ended. denial."

To kick off the show, the pop star joined Fallon for a performance that is polar opposite to hers. She bobs along in the background with a rather sullen face as Fallon, Horatio Sanz, Chris Kattan, and Tracy Morgan give their rendition of “I Wish It Was Christmas Today.” Watch that below.

Also during Tuesday night's show, Fallon sat down to talk to the one and only Michelle Obama. If you didn't know, Obama invented books this year, including her own memoir "Becoming." Check out that interview here.