Actually a work assembly, but they're very much the same.
During the "financial downturn", the new guy heading up our London office called a school assembly to explain why we should all work hard to turn things around.

Unfortunately, I have no idea which presentation he'd used as a template, but for some reason there was a motorbike noise on the slide transition he hadn't noticed on his soundless PC before presenting it to the whole company in our conference room, on a PC that very much had sound.

Dire financial results and discussions of redundancies were therefore punctuated by an increasingly hilarious "vroom, vroom", with many of us mentally contorted as to whether we could admit this was funny, or had to remain serious and professional looking. I think I lasted about 8 slides before collapsing in giggles.

**EDIT: the only difference is that there are fewer hymns. I might suggest adding them in**
( prince-igor si tacuisses, philosophus mansisses, Mon 17 Jun 2013, 12:04, Reply)