Jingle Ball took over T.D. Garden Thursday night with KISS 108 and iHeartRadio. The annual concert presented headliner Scottish DJ-producer Calvin Harris in his full Amadeus glory, atop a multilevel platform stage. The ambiguity of what Harris — who is the world’s high-earning DJ and was paid an estimated $66 million this year, according to Forbes — does behind that laptop remains, but what he lacks in transparency, he makes up commanding a crowd of crop-topped teens to jump and sway.

Of course, there was plenty more to see. A rotating stage! Laser light shows! 5 Seconds of Summer was there. Tove Lo, too! Here are our ICYMI takeaways for the night:

'90s FTW: Nick Jonas got every 30-something on their feet when he added a cover of Boston-bred Bell Biv DeVoe’s “Poison" into his set. Meanwhile, Dutch newcomer Natalie La Rose tried her hand at Crystal Waters' “Gypsy Woman,” a welcomed introduction for all the millennials who didn’t recognize her name, and the tweens who mistook it for an original.

Pitched as perfect: While Hailee Steinfeld's soft spoken cover of Jessie J's "Flashlight" in "Pitch Perfect 2" led to Anna Kendrick's passing of the film's proverbial torch, it doesn't translate to her live stage show. Her self-love anthem, "Love Myself,” set the tone for her first run of concerts, as she led the crowd in a rowdy chant in a gold sequined leotard.

Demi demos: Lovato fans were unmistakably the most aggressive of the pack, flooding the stage screens' Twitter stream with “OMG CRYING, DEMI, SCREAMING. CAN’T.” tweets for the duration of her set. She performed “Mr. Hughes,” a bluesy Winehouse-esque track from her new album, "Confident," informing the Boston crowd it was its live debut. “It was a little all over the place,” she humbly admitted. “But my band sounded awesome."

NSFWO: That’s Not Safe for Wee Ones — it probably should come as no surprise, but the radio edits are off on-stage, and we were all reminded just how explicit The Weeknd can get. And witnessing youngsters singing along to "Talking Body" is pretty horrifying. But, like, yolo.