Spontaneous Song!
Not quite assembly , but a large percentage of the school in one place at one time for an organised event. So it kinda fits the brief.
Mess Hall.

Generally meal times were a bit of ordered chaos. We all queued along a wall (1st in best dressed obviously), got served whichever boiled/deep-fried slop was on the menu and then sat at our allotted long tables on benches shoveling food into our hungry maws. Frequently the piggies would be lining up for seconds before the 1sts line had gone thru completely.
On Sundays we had a chapel service prior to dinner. A long, boring, drawn out service doled out by a preacher whose only belief (I think) was in that of his pension.
But.... The rule was that if you didn't attend chapel you weren't supposed to be able to get tea. Inorite?! Some housemasters adhered to this rule more strictly than others - an interesting correlation was that the housemasters who had themselves been former students tended to be the bigger cunts generally.
One such example was "Warnie" (no relation to the cricketer fighting male-pattern baldness and who waited to fuck Liz Hurley when she was past her prime..).
Warnie was a cunt of the highest order. Amongst his many exploits - he would stand at Mess front door with his roll from chapel and if you weren't on the list you couldn't go in, regardless of why - late getting back from leave? Too bad, go hungry! Just got back from hospital visiting dying Gran, hope you've got some noodles in your locker sunshine 'cause you ain't eating tea tonight! He would even post some suckup prefect at the backdoor to the kitchen as frequently the kitchen staff would take pity on us and give us a few plates out the back.

Thus one night in the packed dining hall someone began humming "Camptown Races", you know - "Something, something, something, something ,do dah, do dah.". Which quickly became "Warnie takes it up the arse, do dah, do dah" and very rapidly turned into
"WARNIE TAKES IT UP THE ARSE, DO DAH, DO DAH!!"
with 400 of us belting it out as loudly as we could until Warnie eventually [with as *little/much* dignity that he could muster - REDITED for pikey] arose from the teachers table and left the dining hall as quickly as he could.
No-one could tell where it had begun. There was no point in a witch hunt as every single one of us had been in full voice. Leave for the entire boarding house community was canceled that weekend as punishment but the consensus was that it had been totes worth it.
Warnie managed to never be on duty for chapel on a Sunday arvo ever again and left under a cloud later that year anyhoo.

Tl;dr? - we questioned a housemaster's sexuality en masse, in full song because he was mean to us.
EDITED 'cause I found the right song.
(Misery McUglywife an attention seeking sociopathic fuckstain., Tue 18 Jun 2013, 22:24, 11 replies)

But isn't homosexuality the norm at boarding schools?

( drimble he'd been white, he'd been black, Tue 18 Jun 2013, 22:26, closed)

Never use "bugger"
as a swear word in case someone takes it as an invitation.
(Misery McUglywife an attention seeking sociopathic fuckstain., Tue 18 Jun 2013, 22:37, closed)

Your mother spent a small fortune
sending you to a school for young toffs, hoping some sort of class would rub off on you.
I hope you have apologized for wasting her money.
(the other guy not the one that gave you coochie warts, Wed 19 Jun 2013, 0:23, closed)

Fucken' oath!
EDIT: It should be said in all seriousness tho that if I ever thought that I had turned out like most of the spoilt, entitled and generally fucked up bunch that were my classmates I would've deleted my account and killed myself many, many years ago.
(Misery McUglywife an attention seeking sociopathic fuckstain., Wed 19 Jun 2013, 0:31, closed)

I'm glad that you're able to rationalize it

(the other guy not the one that gave you coochie warts, Wed 19 Jun 2013, 1:50, closed)

You should really change your spellcheck from en_US
to en_AU or at least en_GB so that we can understand you.
(Misery McUglywife an attention seeking sociopathic fuckstain., Wed 19 Jun 2013, 2:18, closed)

Somehow I doubt that would help in your case.
Try phonetics. Sound out the words. ra she an Al eyes
(the other guy not the one that gave you coochie warts, Wed 19 Jun 2013, 3:31, closed)

Rashy Anal Eyes?
Probably shouldn't rub them before you've washed your hands then...
(Misery McUglywife an attention seeking sociopathic fuckstain., Wed 19 Jun 2013, 5:51, closed)

The whole theory of modern education is radically unsound. Fortunately in England, at any rate, education produces no effect whatsoever.
( Wanderer, Thu 20 Jun 2013, 8:31, closed)

I'm Australian.
We have the Brain Drain. Luckily I stayed behind to balance the books.
(Misery McUglywife an attention seeking sociopathic fuckstain., Thu 20 Jun 2013, 9:03, closed)

Yeah hahaha

(woocfot friends with Sacha Distel, Wed 19 Jun 2013, 1:49, closed)

(Misery McUglywife an attention seeking sociopathic fuckstain., Wed 19 Jun 2013, 2:35, closed)

*imbecile

( janet aylia y'all motherfuckers need jesus, Wed 19 Jun 2013, 8:31, closed)

Hahahahahaha

( Je suis un vagabond is an unfunny, up your own arse middle class knob, Wed 19 Jun 2013, 8:53, closed)

10 points to Slytheryn.

(Misery McUglywife an attention seeking sociopathic fuckstain., Wed 19 Jun 2013, 10:50, closed)

fuck's sake

( The Doveston haunted by the memory of his own amnesia, Wed 19 Jun 2013, 11:38, closed)

What does
Fuck's sake have to do with this?
I don't even like distilled rice wine and I certainly wouldn't drink some from someone called "Fuck".
Cheers.

EDIT:Because getting upset 'cause I misspelled the name of a house at Hogwarts in Harry Potter books doesn't make you look like a saddo at all. In any way shape or form.
(Misery McUglywife an attention seeking sociopathic fuckstain., Thu 20 Jun 2013, 3:41, closed)

fucking hell

( The Doveston haunted by the memory of his own amnesia, Thu 20 Jun 2013, 9:39, closed)

Are you?
Still it's probably less painful than rashy anal eyes, right?
(Misery McUglywife an attention seeking sociopathic fuckstain., Thu 20 Jun 2013, 9:47, closed)

Why was he rising from the table with 'as little dignity as he could muster'?
One would have thought that 'Warnie' would have actually behaved with as much dignity as he could muster, given the circumstance of him being an authority figure who was being publicly mocked; why 'as little dignity'? why the levity?

Unless you are somehow connecting the notion of 'he had very little dignity as I recall' with ' he did try to muster some dignity' and this has unfortunately somehow led to the erroneous/misleading phrase "as little dignity as he could muster".

If that's true then I reckon old 'Warnie' was dead right to starve the lot of you: you clearly weren't even paying attention to your own over-priced education.
(pikey, Wed 19 Jun 2013, 3:04, closed)

Or....
This is /qotw where grammar comes a close second to the concept of "comedy website lolz"?

Nonetheless I'll fix it for you. If that will appease your sense of righteousness. Nice use of a colon btw.
(Misery McUglywife an attention seeking sociopathic fuckstain., Wed 19 Jun 2013, 4:33, closed)

It's not a grammar problem if you use the wrong word for the meaning that you're trying to convey.
'Little' is the opposite of 'much' and has the opposite meaning. Honestly, I wonder sometimes if I'm the only one who regards his 'comedy website lolz' with the appropriate level of pedantry and seriousness.
(pikey, Wed 19 Jun 2013, 4:46, closed)

I know, right?

(Misery McUglywife an attention seeking sociopathic fuckstain., Wed 19 Jun 2013, 4:49, closed)

And, thank you for the edit.
Perhaps I'll be able to sleep now.
(pikey, Wed 19 Jun 2013, 4:50, closed)

Rest easy dear friend.
And make sure you wash you hands before you rub your eyes.
(Misery McUglywife an attention seeking sociopathic fuckstain., Wed 19 Jun 2013, 6:02, closed)

*your*
PEDANTILOLZ.
( Infidel , shit and wrong, Wed 19 Jun 2013, 14:13, closed)

Bugger!
You rashy anal eyed imbicile!
(Misery McUglywife an attention seeking sociopathic fuckstain., Thu 20 Jun 2013, 1:11, closed)

you're eyes

( drimble he'd been white, he'd been black, Thu 20 Jun 2013, 1:33, closed)

Although, when I read it now..
the inclusion of brackets and the reference to the edit just ruins the flow and confuses the reader. You'll have to change it back, I'm afraid. At once.
(pikey, Wed 19 Jun 2013, 23:16, closed)