Once upon a time when I was but a wee girl, your TV set would go wonky. The picture would tip sideways or develop horizontal lines or a loud hiss would interfere with the sound, necessitating adjustment: fiddling with the aerial or finely adjusting the Horizontal and Vertical Holds, each interspersed with appropriate curses. Like mantras in a ceremony it was important to get these right, viz: ‘Stupid bloody box – twiddle – why – bend – don’t – twiddle – you – sodding well – shove – work! These occurrences were not infrequent but sometimes the problem would be at the Other End ie the TV company: at such times a sign would be displayed saying ‘Do Not Adjust Your Set.’ Then would follow the celebrated Test Card. And some music, usually of the plinky-plonk variety.
As a sort of hommage to this phenomenon a programme was made for children called Do Not Adjust Your Set. I loved this, short-lived though it was, and only much later realised that it was proto-Python, being made by some of the same team:
I had a serious point to make but my mind-set has gone all wonky now. I’ll try giving it a shove.
Nope, I’ve lost the picture. And now the sound’s going. Oh well, here’s some plinky-plonk music instead.