Taylor Swift joined by Beyoncé for The Eras Tour film premiere

Swift, wearing an Oscar de la Renta full-length blue gown, posed with her fans and fellow celebrities on the red carpet.

"I've always had fun doing this. I can't believe I get to do music as a career. That's crazy," she said.

The Eras tour was "the most electric experience" of her career, she added."I've never had this much fun in my life as I have had on The Eras Tour.

"We did this show rain or shine, in sickness and in health, no matter what was going on in our lives. And we did it with a grin on our face because [of] what greeted us on the other side."

The film was shot over the course of three concerts in Los Angeles' SoFi Stadium in August, and the set list includes tracks spanning her whole career.

However, the sprawling, four-hour live show has been edited for the cinema, with fan favourite tracks like Wildest Dreams, The Archer and Cardigan missing from the running order.

It will be released in the UK on Friday, but Swift has announced last-minute "early access screenings" for fans in the US, due to "unprecedented demand".
 

Details ahead of Wednesday's premiere were shrouded in secrecy, with select fans receiving invitation-only tickets for opening night via Spotify.

The venue - a 14-screen cinema in an upmarket shopping centre in Hollywood - was completely closed down to accommodate the throngs of fans.

With hours to go, it was still not confirmed whether Swift would be in attendance, but fans erupted as the star appeared just moments before the action began.

The movie has already generated more than $100m (£83.2m) in advance global ticket sales. That makes it the biggest concert film of all time, overtaking Justin Bieber's Never Say Never, which made $99m (£80.5m) in 2011.
 

Unlike normal film screenings, Swift's three-hour extravaganza will only be in cinemas on Thursdays, Fridays, Saturdays and Sundays; and it is expected to have a limited release of around four weeks.

Team Swift only wants packed crowds to experience the film, almost as if it's a real concert. They don't want half empty cinemas on a lonely weekday afternoon.

It's classic Taylor all the way - even down to the ticket prices.

In the US, ticket prices before tax are $19.89 for adults - a nod to her album title and the year she was born - and $13.13 for children, with 13 famously being her lucky number.

Security at the premiere on Wednesday was extremely tight, with multiple ID and ticket checks, metal detectors and bag searches. Swift fans clutching their tickets faced a lengthy wait.

Not that it bothered them.

"I'm so excited to be here right now," exclaimed 21-year-old Kate McGovern. A native of San Diego, she told the BBC she had taken the day off work and college to make the nearly three-hour journey to Los Angeles.

"I'm just like, overwhelmed right now. I'm, like, shaking a little bit, a little bit anxious. My stomach hurts, but, like, in the best way possible. I have, like, no expectations for tonight. I'm just excited."
 

Caroline Schneider, an LA local, only found out on Monday that she had won tickets.

"I can't believe this is happening, because it's also so unusual for music artists to release a concert film in this way, in this fashion," she told the BBC. "And then to have an event like this where just hundreds of fans are invited to come and enjoy the concert again, with each other is really cool. Right?"

Swift's appeal is almost unprecedented - even for music, an industry used to attracting devotion to its biggest stars.

"She represents the new mega star," says Sanjay Sharma, a business professor at the University of Southern California in Los Angeles. "She's not only a successful artist with a huge global following, she's also a very smart businesswoman."

So much so that the economic juggernaut that rolls into town when Taylor Swift is performing has its own name: "Taylornomics."

Mr Sharma estimates that Swift's six performances in Los Angeles added 1-2% to the local economy.

That's because Taylor Swift tourists are not just paying for a concert ticket. There are aeroplanes, hotel rooms, meals out, and outfits to buy. Local businesses are leaning into the effect by hosting Taylor targeted events with pop-up bars and karaoke nights.

But the success of the tour and film is largely down to her music and an intensely loyal fan base.

"She's got an audience of people who didn't get tickets. And then she's got an audience of people who did get tickets and want to live it over again," said Elizabeth Scala, who teaches a college course on Swift at the University of Texas in Austin.

"And I think that's really who's going to see the film. I don't really think anybody's going out of curiosity to see the film."

As Taylor's fans know all too well, Taylormania could go on forever. But for the legions of fans that flocked to Los Angeles on Wednesday, the real goal was to catch a fleeting glimpse of their hero.

"That would make my dreams come true," Kate McGovern confided to the BBC.

"I'd probably die happy that way."