Smoking in the washroom.
I have a memory from Westmount High School back around 1971.
It was common in those days to sneak into the boys washroom across from the cafeteria to have a quick smoke.
Sometimes the stall would get quite crowded with participants, all sharing a single cigarette. The cigarette would develop a "heater" as we called it from being puffed on and quickly passed around. The paper would turn brown. Curiously, I don't remember anyone ever getting "caught" even though it was as regular as class changes.
So one day I was in there with Mark Waind and Chris Saunders. I was drum crazy in those days, always drumming on something. On this occasion, I was drumming away on the heater cover when Chris formed a trumpet with his hands and fingers and started to belt out a bunch of flud-uts.
Flud-ut da dut-dut dut and so on.
Then Mark joined in with his version of a trombone or something. I started to add my own version of a vocal tuba or bass or something. (Going by memory here.)
It turned out to be one hell of a little jazz session.
Every little while, as if perfectly scripted, the music would come to a sudden stop and the three of us would below with laughter, then, just as seamlessly, we'd start "playing" again.
We had a great time. Needless to say, tobacco wasn't the only thing we smoked that day.