Last night I went to the Taylor Swift concert in London, the first she has performed since her three shows in Vienna were cancelled because of a terrorist threat.

And the first since a knife attack at a Taylor Swift-themed dance class in Southport left three children dead and ten others wounded, with five of them still in a critical condition.

These tragedies carry their own weight of heartbreak and inconsolable loss, but it seems particularly piercing that the cluster of malevolence should gather around Swift, a performer who has spread nothing but joy around the world since her Eras tour began in March 2023.

For her and us, it was an emotional return to the stage, our mutual presence a fightback against the forces of darkness.

‘Well hello, London, we have arrived!’ she cried after performing Cruel Summer at the start of her show. ‘Well fancy meeting you here at Wembley Stadium,’ she added, looking emotional at the rapturous welcome from the 92,000 crowd.

By the time all 150 dates on the world’s biggest ever concert tour end in December, more than six million people around the globe will have enjoyed her performances. A year ago, I first saw the Eras tour in Los Angeles, marvelling at the stamina, the glamour and the sheer heart and soul Swift poured into the three-hour show. It was hard to know who enjoyed the experience more – the delirious fans or the star herself.

Yet standing among the crowd at Wembley it felt like something had changed; that an innocence had ended, a carefree sense of pure pop happiness had been lost, perhaps for ever. Not among the younger fans, still with their gauntlets of friendship bracelets, palpitating with excitement as they bellowed the lyrics and danced until their tiny feet hurt.

A thread on Mumsnet this week revealed that some mothers now thought that attending any of the five Swift concerts in London was ‘too dangerous’. ‘If there were any threat, Taylor would have cancelled,’ someone wrote on X, putting impossible responsibility on the shoulders of a celebrity who already sees the safety of her fans as paramount.

Some are annoyed that Swift has not publicly condemned those who have been arrested in Vienna, nor the organisations to which they are said to be affiliated.

Yet isn’t it likely that she has been advised by security services not to acknowledge, taunt or defy Isis – because to do so might put herself and her fans in further jeopardy?

These are the terrible times we live in. It has become clear that any mass public event now constitutes a potential terrorist threat – and that iconic pop stars such as Swift who attract huge audiences will also attract, through no fault of their own, the attention of death cult fanatics who simply want to destroy and terrify.

Details of the putative attack in Vienna are horrifying: the Islamic State and al-Qaeda literature read by at least two of the arrested suspects, the explosives in their possession, the plans to move through the crowd with knives and God knows what else, killing ‘as many as possible’.

Murdering happy little girls in sparkly dresses? One wonders what kind of sick ideology or organisation believes it could benefit by such cowardly brutality. Yet performers, promoters and parents are asking, how can we keep audiences safe? And wondering if it is only a matter of time before another atrocity.

London mayor Sadiq Khan said that while he understood Vienna’s reasons for cancelling, his city was ‘going to carry on’. Khan insisted that the capital’s authorities were prepared for shows there following lessons learned from the 2017 Manchester attack, where an Isis suicide bomber murdered 22 people at an Ariana Grande concert.

But what about – a tiny voice inside me says – the lessons we have yet to learn? What about the unknown unknowns? Yet to let your thoughts wander down that route is to invite paranoia and madness; it is to let the terrorists win.

Security at Wembley was tighter. There was a heavier police presence than her shows here in June, along with sniffer dogs trained to detect explosives, knife- and metal-detecting arches and handbag searches.

I even had to show my notebook – a first. And there was strictly no Tay-gating. The joyous practice of ticketless fans congregating outside stadiums for a communal singalong is over. That’s sad but perhaps inevitable.

But, despite tiny misgivings and fleeting worries, I went along, like thousands of others, and I wore my sequins, each one a tiny badge of defiance and hope, because it is important to sparkle against the darkness. You cannot let them win. What a show and what a woman. Not only could I not have felt safer, you could have fuelled a rocket to the moon and back on the sheer joy of it all.

No matter how successful, adored and famous a pop star becomes, there will always be a grump in the corner moaning that they can’t see what all the fuss is about. Usually that grump is me, but not when it comes to Taylor Swift. I love Taylor’s songs and her admirable, demented work ethic, which crested this month with the release of two new albums — The Tortured Poets Department and The Anthology — both written, recorded and made while she is in the middle of her worldwide Eras tour, performing on stage for three straight hours at every show.