Charli xcx may spend the rest of her career ping-ponging from one varied sound to the next, but few of her switch-ups could ever possibly compare to the pivot she initially announced this year with the debut of Music, Fashion, Film lead single (and album opener) “Rock Music.” As the song came into focus on Monday night — with Charli donning a t-shirt proclaiming “I’ve Had Sex With Charli xcx” — the entire era felt immediately validated by the first “ro-o-o-o-o-ock” Auto-Tune glitch, a brilliant piss-take that cackles at you for taking it seriously while still being far too undeniably cathartic to truly laugh off.

“I’ve been talking about playing old songs from different albums,” Charli rhapsodized after a quick selection of older songs partway through her set, before intro-ing a tour first-timer: “I thought this would [be good for] New York.” That apt selection was “Next Level Charli,” gleefully bombastic opener from 2019’s underrated Charli set — a valuable reminder that even outside of her most obvious cult favorites, critical favorites and commercial favorites, Charli has an entire catalog of gems always waiting to be dug into.

“Dying for You,” from Charli’s Wuthering Heights soundtrack released earlier this year, was a much-appreciated “Oh right, this song” selection from a set that already feels historically underappreciated. But more significant on Monday night was what it led into, as a quick “You ready?” Charli transition led to it giving way to an entire spate of stakes-raising Brat smashes: “Club Classics,” “365,” “360,” “Sympathy Is a Knife” and “Von Dutch,” for starters. If you weren’t ready, you’d have better gotten ready right quick, otherwise the fevered Barclays Center crowd was more than prepared to leave you behind for the rest of the show.

Not that Charli xcx ever needs an excuse to play “Unlock It,” one of the most beloved songs off her fan-beloved 2017 set Pop 2. But certainly, having Kim Petras in the building makes it a slam dunk, as the song’s special guest feature appeared to swap vocals with her fellow alt-pop paragon — Charli mostly in black, Kim mostly in white — and have fans once again wishing for some kind of full-project team-up between the two, most likely consisting of nothing but “[Verb] It” song titles.

If you caught one of Charli’s festival sets and hoped she might add some of her older pop classics to the eventual tour setlist, you were out of luck — with one appropriate exception. While none of her trio of 2013-14 chart smashes (“Boom Clap,” “Fancy” or “I Love It”) made appearances on the Music, Fashion, Film Tour rundown, her game-changing 2015 EP title track “Vroom Vroom” did ultimately make the cut — with Charli in control behind the wheel atop her multi-story stage perch, and her pit crew of backing dancers approximating the race-track action beneath her. It might not have been the crossover hit those top 40 bangers were, but it felt more appropriate mixed in with Charli’s past decade of favorites, not to mention the rest of the last 10 years of hyperkinetic pop music.