FOR my dad, the highlight of the decade I spent living in London was that he got to go to The Proms. And, boy, did he go to The Proms. He went to so many proms, in fact, that he was more than eligible to enter the attend-five-expensive-concerts-to-qualify ballot for tickets to the last night and, to his great joy, one year – 2009 – he was successful. I was lucky enough to be his plus one.

Lucky because that year’s programme included Chôros No. 10 by Brazilian composer Heitor Villa-Lobos performed by the BBC Symphony Orchestra and the combined choral forces of the BBC Singers and BBC Symphony Chorus. The sound they created was huge, uplifting and utterly enveloping, and experiencing it was by far the highlight not just of that night but of any orchestral performance I had seen before or since. Even now, a decade later, I get goosebumps just thinking about it.

The second half, though, I think my dad and I could both have taken or left. All that pomp and circumstance didn’t really sit too easy with us and I am pretty sure we were the only ones in the audience not to stand and holler during the highly theatrical rendition of the Thomas Arne staple, Rule, Britannia. It wasn’t just that lyrics about Britons flourishing “great and free” at the expense of nations “not so blest as thee” grated, but that all the flag-waving and singing along felt more than a little bit daft. The whole thing just wasn’t very us.

But that’s the thing about The Proms: despite many of its concerts pushing musical boundaries; despite a programme of free discussion events shedding light on the seeming impenetrability of classical music; and despite the availability of thousands of £6 promming tickets meaning those of slender means still have some hope of managing to attend, for too many people The Proms is the last night, the last night is the second half and the second half just isn’t for them. Given that it’s all so very British Empire, with all the negative connotations that that brings, can you blame them?

Only this year the final event of the eight-week extravaganza was a little bit different. Yes, there was the usual patriotic fare, with Henry Wood’s Fantasia on British Sea-Songs, Edward Elgar’s Land of Hope and Glory, Hubert Parry’s Jerusalem and – of course – Rule, Britannia all featuring. And, yes, there was plenty of union flaggery. But this year there was something else too: a self-styled “queer girl with a nose ring” using an event that to some symbolises the pinnacle of cultural exclusivity to take a very public stand in the name of inclusivity.

American mezzo-soprano Jamie Barton has seemingly never been one to conform, with her love of opera representing “an act of musical rebellion” against parents who raised her to the sounds of bluegrass, the Grateful Dead and The Beatles. Having come out as bisexual in 2014, she used her appearance at this year’s Proms finale to stage another act of rebellion, subverting the chauvinistic undertones and overtones of Rule, Britannia by performing it in the colours of the bisexual flag while waving the distinctive rainbow Pride flag high above her head.

It was a gesture, she said, that was designed to “make a very clear statement of pride”, tweeting afterwards that “it was an honour to wave a flag that stands for inclusivity, diversity, and above all, love”.

Her actions certainly had a positive effect for some, with the Proms audience in the Albert Hall breaking into spontaneous applause when Ms Barton held her flag aloft and the journalist James Ball, global editor at The Bureau of Investigative Journalism, tweeting that Ms Barton’s actions represented “a moment” for inclusivity. A colleague of mine said witnessing that moment was “wonderful”, adding that “as a gay man, it brought tears to my eyes”.

Not everyone felt that way, though. Jordan Daly, co-founder of LGBT visibility charity Time for Inclusive Education, spoke for many when he tweeted that if Ms Barton waving the Pride flag during Rule, Britannia was a moment it was “a crass one”. “A rainbow flag during Rule Britannia?" he wrote. “There are LGBT people suffering the worst violence and discrimination across parts of the Commonwealth because of the cultural impact of the British Empire’s exported homophobia and sodomy laws. Save this.”

I can certainly see his point. After all, wasn’t it the glorification of empire – of the “dread and envy” Britons could instil in others – that kept my dad and me in our seats back in 2009? And there is no doubt that colonial-era laws are still blighting the lives of LGBT people the world over, with India only last year overturning British-born legislation that banned consensual gay sex on the basis it was an “unnatural act”, while it is estimated that close to 50 former British-administered countries continue to criminalise homosexuality. It is a shameful legacy of a shameful time in our collective history that not one of us can be proud of.

Yet to dismiss the waving of a Pride flag during that particular song, in that particular segment of that particular event, would seem to miss the significance of the moment entirely.

In modern times at least the finale of The Last Night of the Proms has always been something of a camp affair. The Rule, Britannia my dad and I saw back in 2009 was no exception, with mezzo-soprano Sarah Connolly, a singer famed for playing so-called breeches roles, strutting onto the Albert Hall stage dressed as Lord Nelson, saluting and scowling like the best of pantomime villains. Yet despite that it has never seemed a particularly inclusive affair – until now.

Of course it’s right to question whether operatic pieces like Rule, Britannia, whose words most certainly leave plenty to be desired, have a place on modern concert programmes. And of course the idea of revelling in an age-old image of Britishness at this particular moment in history will be repugnant to many. But anything that shows that traditions like the Last Night of the Proms are not the preserve of traditionalists, that meanings can be changed and that membership "rules" can be relaxed, has got to be recognised for what it is – a moment. More than anything, though, Jamie Barton’s moment was A Moment not in spite of its setting, but because of it. That is something we should all be able to take pride in.