There was pandemonium before Taylor Swift’s first Sydney show even started – but the night’s wildest moment came during one infamous song.

Sydney was in its emergency poncho era on Friday night as storms threatened to scupper Taylor Swift’s first concert in the city in six years.

In the end, the only casualty of the wet weather was poor Sabrina Carpenter, who found her opening set nixed at the last minute so Swift’s mammoth show could still run close to schedule.

And in the minutes before Swift took to the stage, pandemonium swept the stadium as a cavalcade of A-list celebs took their spots in a separate VIP section on the venue’s floor.

There was director Baz Luhrmann, actor Toni Collette, celeb couple Taika Waititi and Rita Ora, Swift’s boyfriend Travis Kelce – and there, between them all, was Katy Perry.

Katy Perry in the VIP section at Taylor Swift’s Sydney concert.

Those who’d missed the news earlier on Friday of Perry’s top-secret arrival into Sydney for a private gig this weekend couldn’t quite believe their eyes. Katy Perry? What’s she doing here?

“Not to be dramatic but Katy Perry being at the Eras Tour in Sydney is too much pop legendness to handle in one night,” one fan cried on Twitter.

It was a truly wild sighting but more importantly, didn’t these two used to have … beef?

Swift opens the show in Sydney. Picture: AFP

Rita Ora and Katy Perry watch the show.

In fact, Perry’s surprise appearance at the concert gave Sydney a genuine pop cultural moment late in the show: Swift performed her caustic 2015 diss track Bad Blood as its alleged subject watched on. I was seated several rows in front of Perry, and of course I snuck a glance: Yes, she was bopping along.

Perry also took to Instagram with a video of herself reacting to the dis track, in which she pulls a shocked face before mouthing the lyrics.

The singer also shared sweet selfie alongside Swift which was taken pre-show, proving there’s now nothing but mad love between the A-list pair.

No bad blood here: Katy and Taylor at the Eras Tour Sydney concert.

The celeb-spotting was just one dazzling element of a show that was big on spectacle.

As Swiftmania gripped the country over the past few weeks, several outlets have pointed out Swift’s humble beginnings in this country, compared to her current pop megastar status.

She first performed in Australia at a 2009 Country Music Festival in Thredbo, a comparatively tiny gig that saw the then-upstart country star sing for just a few hundred people.

Yes, she’s come a long way since then – but the same could be said of Swift since her last visit to our shores, too. Swift was last here in late 2018, performing four shows around the country for the Reputation world tour.

Since then, she’s gone from huge pop star to inescapable pop cultural force: Four studio albums – with a fifth to follow in April – along with four “Taylor’s Version” re-releases of her previous works.

As she told the crowd in Sydney, her hobby during Covid was making “as many albums as humanly possible”.

The result? The general population has been pummelled into submission. Even if you’re not a Swift fan, at this point, you really can’t escape her.

Fans got pelted with rain on the way in – but miraculously, the rain held off during the show. Picture: DAVID GRAY / AFP

For fans who’ve followed her whole career, The Eras tour is an almost overwhelming prospect: An exhaustive journey throughout her entire musical career to date.

I’ll admit that when the tour was first announced, I was a little disappointed at the prospect: Her lockdown albums folklore and evermore contained some of her best-ever music; couldn’t they get their time in the sun instead of a greatest hits show?

I needn’t have worried. Songs from those two albums get about a dozen spots on the Eras setlist.

Swift’s show is a three-and-a-half hour spectacular. Picture: Don Arnold/TAS24

Her boyfriend Travis Kelce with Rita Ora.

And that still doesn’t even equate to a third of the show, as Swift spends almost three-and-a-half hours covering hits and fan favourites from almost every album to date.

Swift’s fanbase is so huge, so voracious, that just about any song of hers could qualify as a greatest hit nowadays (case in point: Cruel Summer, a 2019 album track that somehow, inexplicably became a huge global hit over the past six months).

Still, it’s a brave choice to open the show with the stunning Miss Americana & the Heartbreak Prince, a moody, Lana Del Rey-indebted album track.

From then on, the setlist is perfectly crafted, Swift wisely eschewing a chronological run through her hits to give the mammoth show the peaks and troughs it requires.

Taylor Swift hangs with Taika Waititi and Rita Ora backstage.

She knows a dozen songs from the largely acoustic folklore and evermore back to back would leave some heading for the bar; so the two records are separated by some of her most bombastic moments, like the pounding … Ready For It? and Don’t Blame Me from reputation.

When the smaller Swift-and-guitar moments do come, they bring welcome moments of intimacy to the massive stadium setting.

And her generosity as a performer – a 45-song setlist! – extends to her opening act: Declaring the tough call to cut Carpenter’s set a “crime against Sydney,” she invited her opener on stage late in the concert to perform a sweet, piano duet together.

Such is her work rate that Swift will have another 70-odd shows of the Eras tour to perform after her next album, The Tortured Poets Department, drops in April.

Will this three-and-a-half hour show then stretch to four, as she adds new tracks from her eleventh studio album? At this point, you wouldn’t put it past her.