As the sun sank toward the skyline and the first few notes of Lisa Hannigan and Aaron Dessner’s performance echoed around City Hall Plaza on Friday night, I thought I knew what I was getting myself into. Maybe it’s that their delicate acoustic stylings were reminiscent of last fall’s folk-heavy lineup. Maybe it’s that, seven festivals in, it had all started to feel a bit routine. Whatever it was, I was way off the mark.

This year’s Boston Calling was not business as usual.

Few things could’ve provided as apt a metaphor for the festival’s sudden growth as Sufjan Stevens’ wildly over-the-top set on Friday night. Smashing a banjo on the stage after his first song, he meant to convey he wasn’t about to deliver the anticipated sad-guy folk performance, but the synth-heavy, technicolor spectacle that followed doubled as the first sign that this would not be the Boston Calling we may have expected. Perhaps sign is too mild a word. It was more of a neon-flashing, all-caps billboard, announcing: STRAP IN, FOLKS. BOSTON CALLING IS ALL ABOUT THE STAGE PRODUCTION THIS YEAR.

Sufjan Stevens
Jess Barnthouse/Wicked Bird Media

And what a production it was. Though Sufjan’s recent, highly acclaimed Carrie and Lowell was somber and subtle, as he cranked up Friday’s kaleidoscopic set, he told the crowd to expect anything but. “We’d like to have a little fun tonight,” he announced in the biggest understatement of the weekend. “A little fun” turned out to be a maximalist affair involving cheerleading-inspired choreography, oversized angel wings, neon projections, and a balloon- and tinsel-heavy monstrosity of a costume that prevented anyone (Sufjan included) from taking the performance too seriously. It offered something unforgettable to diehard fans and curious bystanders alike. Since Boston Calling has historically emphasized performance far beyond production, it wasn’t just an exciting set; it was one that hinted at the festival’s next-tier ambitions.

In contrast to Sufjan’s over-the-top energy, Sia’s headlining performance commanded the top of Friday’s bill with cinematic composure. Belting while poised stock-still on a platform to the side of the stage, she anchored the scene as dramatic, near-narrative choreography unfolded around her, flanked by prerecorded (but carefully synced) jumbotron videos featuring performances by Tig Notaro, Kristen Wiig, Paul Dano, and Maddie Ziegler. Even when the dancers slipped out of sync, the effect remained, and Sia’s set was among the most complex and comprehensive pieces of artistry that the festival has seen in its entire run. In the past, Boston Calling’s Friday lineups always felt like a bit of a warmup to the weekend action, but no more: this Friday night already felt bigger than anything the plaza had seen yet.

Jess Barnthouse/Wicked Bird Media

But dramatic production and unexpected twists come at a risk, and never more so than with Robyn’s performance as Saturday night’s headliner. With a now decades-long knack for arranging triumphant hooks and exultant melodies against driving club beats, Robyn was supposed to head up the dance party of pop perfection that we’ve been waiting for ever since the lineup was announced back in January. Instead, she kept the singing to a minimum and delivered a polarizing remix set that dove further into house and samba influences than it did into the megahits that the crowd had been counting on. A dazzling, mirrored stage setup and slew of acclaimed guest producers didn’t win the plaza over; the entire performance felt like it was building to a hook that never dropped. Maybe the sun-baked audience was too burnt out to dance, but more than anything, it seemed like they just weren’t feeling it, further evidenced by the way the crowd noticeably thinned just twenty minutes in. When Robyn closed out the performance ten minutes early, it gave way to a grumbling through the crowd: what was that? Though the set was intended to treat fans to a rare glimpse at a different facet of her artistry, the point it really made was that festival audiences aren’t the ideal testing ground for new — or heavily remixed — material.

Luckily, some highlights were buried in the festival’s undercard. Saturday afternoon’s Courtney Barnett set caught the Aussie singer/songwriter just a week after her Saturday Night Live debut, and she fully lived up to the hype with a performance that played up her rock edge. Janelle Monaé arguably stole Sunday’s show from headliner Disclosure with a flawlessly choreographed performance that fused pop, funk, and soul influences, matching a slightly retro vibe with an urgent message about identity and equality. Just when we thought it couldn’t get any better, she capped off the performance with a tribute to her mentor, Prince, in the form of a pitch-perfect cover of “Let’s Go Crazy” that got security guards dancing and even the most stolid pit photographers singing along. Not to be bested, the sisters of Haim followed up by reminding us why they’re still fit to top bills with material from an album that came out 3 years ago, delivering a thunderous set of ass-kicking, 80’s-infused pop-rock, featuring a cover of Prince’s “I Would Die 4 U” and a stunning 4-person drum solo. Even artists in the opening slots — Palehound, Michael Christmas, Lizzo, and Christine and the Queens in particular — all came through with powerful performances that would’ve felt right at home later in the day.

Jess Barnthouse/Wicked Bird Media

More than anything, this year’s festival felt like a dramatic experiment in identity. With one foot firmly planted in its indie pop and rock roots, Boston Calling is suddenly branching out in too many directions to make for a single easy narrative, but from crafting a dynamic, diverse lineup to embracing undersung local talent, it seems like curators and producers are starting to catch on to what the city really wants. Though this weekend suggested that Boston Calling is still figuring out exactly what it should be, it also promised that its evolution — especially come next year’s move to Lower Allston — will be an exciting process to watch.