Harriet Walker: Karaoke is always so harmonious – at first

If you want to know more about the world you live in, go to a karaoke night. And I say that as someone who is tone-deaf but who, by the end of the proceedings, is convinced her register is both strong and varied enough to attempt "Wuthering Heights" and "Shaft" within minutes of each other.

At an East End pub last week, I saw humanity come together, and then rapidly divide, over the pleasures of a simple songbook. This was no "Little Brown Jug" round the old joanna; it was Bone Thugs-n-Harmony with a backing track of Woodbine coughs – Tina Turner as sung in octogenarian (male) falsetto. It was my friend Thom, who I never before realised sounds just like Bobby Brown.

As with many Eastern traditions, karaoke brings enlightenment and self-discovery. It helps you realise things about yourself: initially, that you're a self-conscious stick-in-the-mud with too much regard for your own credibility, and then quickly, that you're effin' Pavarotti so gerroff the stage if you're not even going to sing it properly, and let me have another go. Et cetera.

At the beginning of an evening, a karaoke night is the perfect vision of society, a utopia of inclusion and friendliness. Everyone is diffident, all a little anxious about their abilities, willing to defer to those who know what they're doing. Happy to appreciate talent and nurture the under-confident; to ignore the amateurish, smile politely at the caterwauling and not make one single judgement, in case the rules of karma come back to bite them on the arse and they swallow their false teeth during their own turn in the spotlight. Even the regulars – the ones who come prepared with their own headsets – are magnanimous towards the underdogs.

That's at the beginning.

By the end, what you have is the musical equivalent of austerity government – a regime so brutal, callous, inward-looking and self-obsessed as to perfectly reflect our current leaders and the mortified, recessional electorate who voted the buggers in. It's every man for himself when the "no more requests" sign flashes up on the screen, and twentysomething rudeboys start pretending their name is Glenda just to have a go, heedless of whether they're singing Karen Carpenter or Eminem, just desperate to stand on the stage and hold the microphone nonchalantly by its neck, à la Glenn Hoddle belting out "Diamond Lights".

By then, it was like a Hieronymus Bosch painting: all limbs and teeth. And the man who owned the equipment was forced to track down the microphones like a Witchfinder General after one beneficent performer circulated them round the crowd in order to better focus on his dance routine.

It was a great night, regardless. As far as I can tell, since the Olympics people (in London at least) have felt more disposed to celebrate for even the flimsiest reasons. That's the most interesting thing to have come out of the whole sporty affair: show a slightly drubbed and demotivated populace a valid excuse for a party and they'll start finding them everywhere. You finished your pint, you say? I'm so proud of you, that calls for three more. You've renewed your tax disc? Come here and give us a kiss. What are you up to tonight? Oh, my friend made a really good potato salad earlier so I'm going round to celebrate it.

Is this a bad thing? Are we too easily swayed from workaday to demob happy? Does it make you not-a-serious-person? More and more I feel my weekends are like so many school holidays, full of sparkle and fun, a big sociable group-hug of potentially giggling from the minute I leave work on a Friday until the exact moment I put the light out on Sunday night. It's infectious: we all caught it over the summer.

That's why I'm not too broken or bowed by the fact it has started to go dark at 2pm again. The blossoms and bulbs may have been all gaudy in the spring; the Easter lambs are practically adolescent now, not so much gambolling as gambling, and smoking fags over by the water-trough. The new beginnings that sprung back then are tired, but we're all still pepped – like hamsters on wheels – because the summer that followed was more wash-out than wicked.

I'm only too happy to continue enjoying my weekends like an amnesiac. Come Friday, I forget all my troubles and the fact I still haven't instigated a proper filing system in my house beyond putting everything on the bedroom floor under a pair of high heels. I'm like a 1970s labourer clocking off and looking forward to having a curry, having a fight and then passing out.

Likewise, karaoke is for fun-nesiacs: brilliant at the time, remembered with a warm glow but ruined by the sentient presence of cameraphones. And on that note, to the man whose musical turn I forced my friend to video because it was so hilariously awful, I'm sorry. I hope you enjoyed the rest of your weekend.